egg/C xo

ABSTRACT
THE RHIZOME ANATOMY OF THE FERN

GENERA NOTHOLAENA AND PELLAEA WITH A REVIEW OF STELAR
CONCEPTS AND ONTOGENETIC DEVELOPMENT

By
Joseph Howard McCulloch III

The “Cheilanthoid” ferns, considered to be the genera Cheilanthes,

 

Notholaena and figllgggDPlus other smaller genera, are an assemblage of
closely related species. A literature review of work done on the three
main genera is included and illustrates the complexity of the group.
The rhizome anatomy of selected species of Notholaena and Pellaea were
examined to detail the stelar condition, tissue organization and com-
position, and to try and determine if the stele type could serve as a
diagnostic character in identification of the three genera. A review of
the literature of rhizome descriptions of various fern genera and, in
particular, Pellaea and Notholaena revealed two things: first, that
there was very little anatomical information available concerning these
two genera; second, that there were many discrepancies in the descrip-
tions of stelar types. There were a variety of interpretations and
opinions as to stelar conditions as they exist in the ferns. The
solenostele is the dominant stele type in figllgggnand Notholaena, with
the transitional stele type occurring frequently and the dictyostele
occurring in Pellaea only. An examination of the xylem (by maceration

and longitudinal sections) of some Notholaena and Pellaea Species

Joseph Howard McCulloch III

confirmed the fact that the metaxylem is composed of scalariform
tracheids. Although it is impossible to determine, in cross section,
protoxylem from metaxylem, the former's presence is attested to by the
occurrence of helical tracheids. An examination of the ontogenetic
development of the rhizome stele in Pellaea viridis confirms the con-
cept that the vascular cylinder is protostelic at first. The stelar
condition of Pellaea and Notholaena probably cannot be used as a diag-

nostic character to separate the two genera until many more taxa are

examined.

THE RHIZOME ANATOMY OF THE FERN
GENERA NOTHOLAENA AND PELLAEA HITH A REVIEW OF STELAR
CONCEPTS AND ONTOGENETIC DEVELOPMENT

By
Joseph Howard McCulloch III

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Botany and Plant Pathology

1977

ACKNOWLEDGMENTS

We would like to thank the Center for Latin American Studies for
providing a grant that allowed us to collect, in Mexico, many of the
Species considered in this research. We also wish to express thanks to
the following individuals for supplying us with Specimens: Mr. Brown,
Dr. Hoover, Dr. Pinkava, Mr. Rodin, Dr. Seigler, Dr. Schelpe, Dr. Taylor
and especially Dr. Knobloch. We express gratitude to Dr. Schelpe for
his aid in identification of Pellaea viridis v. viridis and to Dr. White
for his personal interpretations and opinions of some of our research.
We are grateful to Michigan State University (Department of Botany and
Plant Pathology) and Normandale Community College (Department of
Biology) fOr the use of their facilities while conducting this research.
We extend personal thanks to each member of our graduate committee: .
Dr. Drew, Dr. Enochs, Dr. Taylor and Dr. Weidlich fOr their help and
consideration during our studies and research at Michigan State Univer-
sity. We especially express gratitude and thanks to Dr. Knobloch.
committee chairman. without whose critical evaluation. guidance.
dedication. endurance and constructive criticism, this research could

not have been successful.

11

TABLE OF CONTENTS

LIST OF TABLES ............................... ...................... IV
LIST OF FIGURES ............ ........................................ v
INTRODUCTION ..... ............. . .................................... 1
LITERATURE REVIEW ................................ ..... .... ......... 8

Morphological ........... ....... ... ..... ........ ........... 8
Ecological ....................................... ..... .... lo
Physiology ..... ...... .. l3
Genetics, Cytology and Evolution ........... ...... . ........ l4
Distributional Notes ...................................... l9
Anatomical, Other Than Rhizome ............... ............. Zl
Rhizome Anatomy ..................................... ...... 23
Review of Stelar Definition ............................... 27
Ontogeny - The Stele ............. ....... ........ .......... Sl
Ecology - The Stem ............. ..... ...................... 54

MATERIALS AND METHODS ........ ..... . ........ . ..... . ...... ........ 56
OBSERVATIONS ....................................................... 70
DISCUSSION AND SUMMARY .. .......................................... . 243
LITERATURE CITED .............. ............... .... ........ . ......... 262

O O O

QHZQWEHUOW>

iii

.P.‘

LIST OF TABLES

 

 

 

 

 

 

Page
Table 1. Classification of the Filicopsida. . ...................... 7
Table 2. Dehydration series as modified from Sass (1958). . ........ 59
Table 3. Paraffin infiltration as modified from Sass (1958). ...... 60
Table 4. Section thickness and staining times of Notholaena. ...... 66
Table 5. Section thickness and staining times of 3311333, . ........ 67
Table 6. Stele types of unsectioned Notholaena rhizomes. .......... 140
Table 7. Stele type and xylem parenchyma of Notholaena. ...... ..... 141
‘Table 8. Number of sections examined and stem diameter of
Notholaena. ........................ ........................ ... 142
Table 9. Stele type and xylem parenchyma of 3311333, ........ ...... 232
'Table 10. Number of sections examined and stem diameter of
Pellaea, ............................... ...... .......... ..... .. 233
‘Table 11. Stele types as reported in the previous literature. ..... 254
‘Table 12. Stele types in previous literature reduced to basic
condition. .................................................... 256
Table 13. Refined stele types. ....... . ........................... . 257
Table I4. Notholaena rhizome habit and stele type. ...... . ........ . 258
Table 15. Egllgga_rhizone habit and stele type. ..... .............. 259
Table 16. Notholaena: stele type and sclerification pattern. ..... 260
Table 17. Egfllggg: stele type and sclerification pattern. ........ 261

iv

LIST OF FIGURES

Figure 1. Paper boat to hold paraffin and rhizomes. ...............

Figure 2. (Flow diagram for decerating, staining. clearing and
munt‘ng. ......OOOOOOOOO 0000000000000 O... OOOOOOOOOOOOOOOOOOOOO

Figure 3. Generalized rhizome cross section. ......................

Figure 4. .fl: Aschenborniana. Cortex. Outer half to left.

x100. ......OOOOOOOOOOOOOOOOO0.0.. 000000000000 O 00000000 O .......

 

Figure 5. N, Aschenborniana. Portion of vascular cylinder.
Phloem, pericyCTe and xylem. X100. ......... ......... . ........

Figure 6. N, aurea. Complete rhizome cross section. solenostele.

x40. ......O...‘......OOOOOOOO.....OOOOIOOOOOOOOOOOOOO00......O

Figure 7. N, aurea. Portion of the vascular cylinder plus
adjacent {IssueSO x100. .....0.........OOOOOOOOOOOOOOOOOOOOOOO

Figure 8. N. aurea. Longitudinal section of primary xylem

showing'scalariform tracheids. X400. .... ............ .........
Figure 9. N. bracgypus. Complete rhizome cross section. soleno-
stele."x . ..... ....... ... ......... .... ......................

Figure 10. N} candida v. candida. Complete rhizome cross section.
SOIenOSteIQe 5:16. OOOOOOOOOOOOOOOOOOOOOOOOO00.000000000000000.

Figure 11. N, candida v. candida. Portion of the vascular

cylinder. 0 ...0.0......O0.0.000.........OOOOOOOOOOO......

Figure 12. N. candida v. candida. Cross section of primary

”1”. 4 O OO..........OOOOOOOO......OOOOOOOOOOOOOO0.0.0....

Figure 13. N. candida v. Copelandii. Complete rhizome cross sec-
tion. saenOSEeleO x O 0.00.0.........OOOOOOOOOO00.00.00.0000

Figure 14. N. candida v. Copelandii. Portion of the vascular

cylinde-r-O O 00......O.......OOOOOOOOOOOOOO........OOOOOOOO

 

Figure 15. N, candida v. Copelandii. Longitudinal section of
pr1mry ”I”. 3:400. 0......0.0...OOOOOOOOOOOOOOOOOOOOOOO0.0.0

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62

65
72

74

74

77

77

79

82

85

85

87

89

89

89

Figure 16. N. cochisensis. Complete rhizome cross section,

 

transitional. 250. ............... . ........................... 92
Figure 17. N, cochisensis. Complete rhizome cross section,

solenostele. 735. ............................................ 92
Figure 18. N5 cochisensis. Longitudinal section of primary

xylem. X455. ................................................. 92
Figure 19. N, cochisensis. Stipe cross section. X100. ........... 94
Figure 20. N. cochisensis. Portion of the rhizome vascular

cylinder. X155. ..... ......................................... 94
Figure 21. N. Galeottii. Complete rhizome cross section,

solenostele. X45. .. ...... ......... ........................... 97
Figure 22. N. Galeottii. Portion of the rhizome vascular

cylinder. X155. .............................................. 97
Figure 23. N, Grgzi. Complete rhizome cross section, solenostele.

x40. OOOOOOOOOOOOOOO .000... OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 100
Figure 24. N, Grgzi. Portion of the vascular cylinder. X100. .... 100

Figure 25. N. int errima. Complete rhizome cross section,
solenostele. 715......... ........... . .................... 103

Figure 26. N. Lemmonii. Complete rhizome cross section, soleno-

stele. ‘X45. ... ..................... ................. ......... 105
Figure 27. N, Lemmonii. Portion of the vascular cylinder.
XIW. 0....000000000.000. ..... ......000.00.00.00...0.00.0000...105

Figure 28. ‘N, Lemmonii. Cross section of primary xylem. X400. ... 107

Figure 29. N. limitanea v. mexicana. Complete rhizome cross sec-
tion, trans Itlonal0 X400 ....00..........0000000000000... ..... 110

Figure 30. N. limitanea v. mexicana. Portion of the vascular
cy11nder.aavenEltlous mt. R400 .0...00.00000000000000000000 110

Figure 31. N. limitanea v. mexicana. Cross section of the vas-
cu‘ar cm‘ naer. film. 0000......000. ...... 00.00.000....00000.0 ‘10

Figure 32. N, limitanea v. mexicana. Outer endodermis to xylem.

x4m. .0...0..0.0.0..0..0... ....... ......000...........00......110

Figure 33. N. ngglecta. Complete rhizome cross section. soleno-
stEIQO 74 0 .000

0.......0.........00......0.....00.....0.00000113

Figure 34. N. W39 ate. Oblique section of primary xylem.
X400. .00. 000000 000.000... 0 00000000000 00000.00000000. 000000000 ‘13

vi

Figure 35. N, Newberrzi. Complete rhizome cross section,
solenostele. . ............. . ...... . ....................... 116

Figure 36. N, Newberryi. Portion of the vascular cylinder.
X

1 0 ........0..000....00. ..... . ..... ......0.... 00000000000000 116

Figure 37. ‘N, Newberryi. Complete rhizome cross section, transi-
tiona10 x 0 ......00... 0000000 0.0.00.0 00000000000000 0 00000000 118

Figure 38. N, Newberryi. Complete rhizome cross section, soleno-
Stale. x 0 00.00.00.000... 00000000000 0 00000000000000000000000 118

Figure 39. N. arvifolia. Complete rhizome cross section,
transitTonal. X45. .... ................... . ................... 121

Figure 40. N. rvifolia. Complete rhizome cross section,
transitTonaT. X45. . ......... . .................. . ..... . ....... 121

Figure 41. N, parvifolia. Cross section of primary xylem.
xm. 00.0.0.0.0000000000000. 00000 .00....0000000 000000000000000 123

Figure 42. N. ri ida. Complete rhizome cross section, soleno-
811219.1-0‘507'11 a. x40. 000000 000000000 0000000000... 00000000000 126

Figure 43. N. ri ida. Complete rhizome cross section with leaf
trace afno e. 40. 0000........00000000000000000 000000000000 0126

Figure 44. N, rigida. Portion of the vascular cylinder. X100. ... 128

Figure 45. N. ri ida. Cross section from outer pericycle to

 

 

primary-xv em. X400. ...... ............ . ................ 128
Figure 46. N} Schaffneri. Complete rhizome cross section. three

adventitious roots. solenostele. X40. ......... .......... ..... 131
Figure 47. N, Schaffneri. Portion of the vascular cylinder.

x1m0 00.0000.....0000000000000 00000 .00. 00000000 00 00000000 00000131
Figure 48. N, sinuata. Complete rhizome cross section, adventi-

tious root ana leaf trace. X40. .................... ..... ..... 133
Figure 49. N. sinuata. Portion of the vascular cylinder at

1mrrTghEe }{|G.0. 0.0.0..0.0.0.0...00.000.00.000... 000000 0.0.133
Figure 50. N, Standl 1. Complete rhizome cross section. adven-

titious roo an eaf gap. X40. ........................ ..... . 136
Figure 51. N} Standlsyi. Vascular cylinder. X40. ......... ....... 136

Figure 52. N. Standlgzi. Portion of the vascular cylinder, at
top. XTOO. 00.000.00.0000......00.......0...00.....0..000 ..... ‘38

vii

Page

Figure 53. ‘N, Standle 1. Longitudinal section of primary xylem
showing scalariform tracheids. X400. ............ ............. 138

Figure 54. E, allosuroides. Complete vascular cylinder with
leaf gap. leaf trace and adventitious root, solenostele.

x40. ...............0.0..... ..... 0000.00.00... 000000 ... 00000 0.0144

Figure 55. P. allosuroides. Complete vascular cylinder, leaf
gap and—two adventitious roots, solenostele. X40. ..... . ...... 144

Figure 56. g, allosuroides. Cross section of primary xylem.
x4000 000000 000. 00000 0 0000000000 0 00000 0 00000000000000 0 000000000 146

 

Figure 57. ‘2, andromaedifolia. Complete rhizome cross section
with leaf gap. solenostele. X40. ............ ...... ........... 149

Figure 58. E, andromaedifolia. Portion of rhizome from cortex
to inner primary phloem. X100. ............. ..... ...... ....... 149

Figure 59. N, andromaedifolia. Inner cortex to primary xylem.
x400. 0.0.0.0.... ...... 0.000....0000..0....000 00000000 0. 0000000 15]

 

Figure 60. E, atropurpurea. Complete rhizome cross section, one
leaf gap. one leaf trace and adventitious root. X40. ......... 154

Figure 61. P. atropurpurea. Vascular cylinder, two leaf gaps,
transitTonal. *X40. ........................................... 154

Figure 62. E, atropurpurea. Portion of the vascular cylinder in
center. x . 0.0.0.0000...0.000....00000000.0.00.0...00000000156

Figure 63. E, atropurpurea. Longitudinal section of primary
”1%, scalar11F0m traCheidSo x400. 0000.00... 00000 .00 00 000000 156

 

 

Figure 64. P. brachyptera. Complete rhizome cross section,
adventifious root. solenostele. X40. ............. ...... ...... 159

Figure 65. f, brachyptera. Complete rhizome cross section. two
leaf gaps, two leaf traces, adventitious root, transitional.

X40. 000000..........00....0.00.0...0.00....0....000.......0...159

Figure 66. E, brachyptera. Cross section of primary xylem.

x400. ......000.000.......0...0.0.0.00000000... ....... 000......16]

Figure 67. P. Breweri. Complete rhizome cross section, four leaf
gaps, fEUr leaf traces, adventitious root, transitional.

X40. ......0.0.00..0....00000.0.0.0.0....00.00.....00.0..00....164

Figure 68. N, Breweri. Portion of the vascular cylinder. adven-
titious rOOE, ”I”. x400 .00.000..0000......0000000000000.000164

Figure 69. E, Breweri. Portion of the vascular cylinder in

center. 0 .........0...0...............0.....0...00.0...0.166

viii

0

 

O

Page
Figure 70. '3, Breweri. Oblique section of primary xylem.

x400. ............0..............0...............0.............166

Figure 71. N, Bridgesii. Complete rhizome cross section, one
leaf gap, so enos e e. X40. .................................. 169

Figure 72. P. Brid esii. Portion of the vascular cylinder in
the center. XI55. ............................................ 169

Figure 73. g, Bridgesii. Cross section of primary xylem. X400. .. 171

Figure 74. P. Bridgesii. One leaf gap, leaf trace. adventitious
mt. saenOSte e. x40. .0..0...0....000..0..0....00000....0..17]

Figure 75. P. dealbata. Complete rhizome cross section, dictyo-
55.10.14”. 0.....000.0....0 ..... 0.... ..... .00.......0.....00. 173

Figure 76. N, dealbata. Portion of the rhizome from epidermis

topt . . ..............0................0........0.....0173

Figure 77. P. dealbata. Portion of vascular cylinder or
mr‘steTe. JIIUO. 00.0...00.0.....0000.000....0...0...00.0.....175

Figure 78. ‘2, dealbata. Longitudinal section of primary xylem,
prominent scalariform tracheids. X400. ....................... 175

Figure 79. P. falcata. Complete rhizome cross section, one leaf
gap. solenostele. X40. ....................................... 178

Figure 80. E, falcata. Vascular cylinder and adventitious root.

x400 ........................................0..00..0..0..0....178

Figure 81. P. intermedia. Complete rhizome cross section, inter-
"Ode, saenOStefla x40. 0...........00.......0.......0.0.0.000 ‘81

F19ure 82. f, intermedia. Portion of the rhizome. X100. ......... 181

Figure 83. ‘3, intermedia. Portion of vascular cylinder, note
”I” PGPQNCHVTE. x400. eeeeeeeeeeoeeeeeeeeeeeeeeeeeeeeeeeeeee ‘83

Figure 84. N, lon imucronata. Portion of the vascular cylinder
With adventtous mate x100. ......0...00..........000.0.00.0186

Figure 85. P. lon imucronata. Longitudinal section of primary
xylem. Showing scalarlform tracheids. X400. .................. 186

Figure 86. E, longimucronata. Vascular cylinder with adventi-
tious mt f" pifh area. x100. 0......0....0..0.....0....0....188

Figure 87. P. longimucronata. Complete rhizome cross section.
one lea? gap, adVentitious root, solenostele. X40. ........... 188

ix

Page
Figure 88. P. longimucronata. Complete rhizome cross section,
two leai'gaps. two leaf traces. adventitious root, transi-
tiona]. x40. 0.0.0....0 ..... 0.0.0.000..........00.... 00000 0.0.190

Figure 89. P. mucronata v. californica. Complete rhizome cross
section, four lea? gaps, transitional. X40. .................. 193

Figure 90. P. mucronata v. californica. Complete rhizome cross
section, tfiree lea? gaps, transitional. X40. ................. 193

Figure 91. P. mucronata v. californica. Vascular cylinder, two
leaf gaps, transitional. *XlOO. ................... ....... ..... 195

Figure 92. P. mucronata v. californica. Vascular cylinder, four
leaf gaps, EransiEional. X155. .................. ..... ........ 195

Figure 93. P. notabilis. Complete rhizome cross section. three
leaf gaps, aavenfit ious root. X40. ........................... 198

Figure 94. N. notabilis. Vascular cylinder. transitional, leaf
traces not visiEle. X100. .................................... 198

Figure 95. N. notabilis. Complete rhizome cross section, one
leaf gap.s solenostele. X40. . ...... ............... ............ 200

Figure 96. P. ovata. Complete rhizome cross section, one leaf
gap, advenETETEUS root, solenostele. X40. .................... 202

Figure 97. N, ovata. Portion of rhizome. X100. .................. 202
Figure 98. N, ovata. Oblique section of primary xylem. X400. .... 204

Figure 99. N, ovata. Portion of the vascular cylinder. X100. .... 204

Figure 100. N. mides. Complete rhizome cross section. two
leaf gaps, aaventifious root. X40. ...................... ..... 207

Figure 101. N, pteroides. Portion of rhizome. X100. ............. 207
Figure 102. .N, pteroides. Portion of the vascular cylinder.

1 . ........0..................00....00....... ...... ......0.0 209

Figure 103. N, pteroides. Vascular cylinder. X100. . ....... ...... 209
Figure 104. Skinneri. Complete rhizome cress section, inter-

node, soleno sfele. X40. ...................................... 212

Figure 105. N. viridis. Complete rhizome cross section, adven-
titious Foot 5, tfiree leaf gaps. X40. ......................... 214

Figure 106. N. viridis. Complete rhizome cross section, adven-
titious Foots, two leaf gaps. X40. ........................... 214

Page

 

 

 

 

 

 

 

 

 

 

Figure 107. N, Njgjgjg, Portion of rhizome, cross section.

X100. .................. ........ .......... ..................... 216
Figure 108. N, Njglgjg, Meristele, note prominent endodermis.

X100. .... ..... .. .......... .. ..... ..... ........................ 216
Figure 109. P. viridis. Longitudinal section of primary xylem,

with scalarTTEFEFEracheids. X400. ............................ 218
F‘9“'§.ilfia.2%i.’.‘ 7%" '.“Ti".".':..??'?E’T???.TTTT?'I‘?.?T‘3??.f‘ffffi’i‘: ...... 221
"Widget-Zn?W:..Y???‘.‘T?T.?i3f'.‘i‘?fi.???.T??T.??‘.’: ..... 221
Figure 112. P. X Hrightiana. Longitudinal section of primary
Figure 113. N, X HrigNtiana. Portion of the vascular cylinder.

X100. ............... ............ . . ...................... 223
Figure 114. N, Galeottii. Scalariform tracheid. X400. ........... 227
Figure 115. N, Galeottii. Scalariform tracheid. X400. ......... .. 227
Figure 116. N, Galeottii. Helical protoxylem tracheid. X400. .... 229
Figure 117. N, Standleyi. Scalariform tracheid. X400. ........... 229
Figure 118. N, atropurpurea. Scalariform tracheid. X400. .. ...... 231
Figure 119. (N, atropurpurea. Helical protoxylem tracheid.

X400. .................. ...... ........... ....... ............... 231
Figure 120. N, intermedia. Scalariform tracheid. X400. .......... 236
Figure 121. N, viridis. Scalariform tracheid. X400. ............. 236
Figure 122. N, viridis Solenostelic condition. X40. ............ 238
Figure 123. N, viridis. Solenostelic condition. X40. ............ 238
Figure 124. N, viridis. Solenostelic condition. X40. . .......... . 240
Figure 125. N, viridis. Protostelic condition. X40. ... .......... 240
Figure 126. ‘N, viridis. Protostelic condition. X100. ..... ....... 242

 

xi

INTRODUCTION

The purpose of this research is to examine and report upon the

anatomy of the rhizome in selected species of Notholaena and Pellaea.

 

We shall compare our findings with what has been previously reported in
these genera by others. Especially we shall correlate our findings
with what is known of the rhizome structure of members of the genus
Cheilanthes with the hope that the rhizome anatomy of members of the
three genera listed above will be of diagnostic value in separating the
genera from each other.

The genera Cheilanthes. Notholaena and Pellaea represent a complex
assemblage of organisms containing approximately 325 species (Pichi-
Sermolli. 1N,Jermy, 1973). The species belonging to the genera
Cheilanthes. Notholaena and Pellaea or any combination or segregates
of these genera are commonly referred to as the "Cheilanthoid ferns"
(Hevly, 1963).

Pichi-Sermolli (1N_Jermy. 1973) considers the family Sinopterida-

 

ceae a member of the order Pteridales, of the class Filicidae and the

division Filicopsida. The family Sinopteridaceae contains fourteen

 

genera: Sinopteris C. Chr. and Ching. Aleuritopteris Fée, Cheilanthes

 

Swartz, Myriopteris Fée, Adiantopsis Fée, Aspidotis Nuttall, Notholaena
R. Brown, Mildella Trevisan. Neurosoria Nett.. Choristosoria Mett..
Ngllggg_tink. Cheiloplecton Fée. Ormopteris J. Smith and Doryopteris
J. Smith (Knobloch. Tai and Adangapuram. 1975). Hithin the order

1

 

 

2

Pteridales the fbllowing families are included by Pichi-Sermolli (12.
Jermy, 1973): Pteridaceae. Negripteridaceae, Sinopteridaceae,
Cryptggrammaceae, Parkeriaceae, Gymnogrammaceae, Adiantaceae and the
Vittariaceae.

Bala Krishann Nayar (1970) considered the following classification
scheme for the Cheilanthoid ferns: Class Filicopsida. subclass
Filicidae. order Schizaeales and family Cheilanthaceae (the Cheilanthoid

 

genera; Ngllggg, Cryptogramma, Hemionitis, Bommeria, Trachypteris and
Gyggopteris).

Rolla Tryon (1956) placed the three genera (Cheilanthes, Notholaena
and Pellaea) in the tribe Cheilantheae of the family Polypodiaceae.
Tryon lists fifty-nine species of Notholaena in the western hemisphere,
grading into Cheilanthes in the characteristics of eighteen species and
into Ngllggg.in the characteristics of sixteen Species at the other
extreme.

Copeland (1947) placed Cheilanthes, Notholaena and Ngllggg.in the
family Pteridaceae and treated Notholaena as being an artificial assem-
blage of plants belonging mostly in the genera Cheilanthes and Ngllggg,

Christensen (1938) included the genera Adiantopsis Fée, Sinopteris
C. Chr. and Ching, Doryopteris J. Sm. and Saffordia Maxon in the
Pteridaceae.

M M (Christensen, 1906) and as described by Posthumus
(1924) cited the following genera in the family Polypodiaceae:
Cheilanthes Swartz, Cryptogramma R. Brown, Doryopteris J. Sm..
Nypolepis Bernhardi, ngggg.Lagasca, Notholaena Brown. Ngllggg_Link and

Plagiogyria Mettenius.

3

The number of classification systems for the Cheilanthoid ferns
and ferns in general derive in part from the ". . . different aptitude
of pteridologists to split or to lump, but it depends also on some
peculiarities of the pteridophytes, particularly their antiquity and
their genetic plasticity" (Pichi-Sermolli, ig_Jermy, 1973).

Not only have there been many problems associated with locating
the Cheilanthoid genera within a particular family, but there have been
and still are serious taxonomic questions as to the species composition
of each genus. The following descriptions of the Cheilanthoid genera
illustrate the tedious taxonomic problems and uncertainties relating to
generic and species affinities that researchers have had to c0pe with,
and some of the still unanswered problems that remain to be delineated.

Tryon (1956) published "The American Species of Notholaena," a

 

compilation of Mr. Weatherby's notes, maps and charts, plus taxonomic
interpretations. This treatment included fifty-nine species, seven of
which were divided into seventeen varieties. Within the United States
19 species were listed, Mexico has 34, Central America 7, Greater
Antilles 8 and South America 20, including 9 species and 4 varieties in
Peru. Not all of these are endemic to the countries listed and some
species are found in more than one area.

In his monograph of the genus Notholaena, R. Tryon (1956) pointed

 

out some problems. Notholaena grades suspiciously into Cheilanthes on

 

the one hand (via N, peruviana Desv., N, brachypus (Kze.) J. Sm., and

a few others) and into Ngllggg_on the other hand (N, Nglmggi_Baker,

Nb pgllgg§_fleath.. N, pilifera Tryon, N, chilensis (Fée and Remy) Sturm,
N, peninsularis Maxon and Neath., N, gggg§11_(Maxon, N, Lumholtzii Maxon

and Neath.. N, limitanea Maxon. N, dealbata (Pursh) Kze., N, Fendleri

4
Kze., N, delicatula Maxon and Weath., N, jggggg_Presl, Np ijgg.(Poir.)
Desv.. N, parvifolia Tryon and N, formosa (Liebm.) Tryon).

Notholaena peruviana and N, brachypus are similar to Cheilanthes
in having a slightly to moderately developed marginal indusium and the
others are similar to Pellaea in rhizome scales and their imparipinnate
lamina. Notholaena parvifolia and N, formosa were previously placed in
the genus Pellaea (Tryon, 1956).

Characteristically, Notholaena possesses a flat, unmodified margin,
but sometimes it is revolute and sometimes it is modified into a
marginal indusium. Notholaena species that possess wax can be
distinguished from Pellaea by that character and from Cheilanthes by an
unmodified margin.

From the time of Linnaeus to Desvaux's Prodrome (1827) six of the
entities mentioned in Alice Tryon's (1957) monograph on the genus
Pellaea section Pellaea were included in the genus Ngggig, which was
one of the major and larger fern genera of the earlier botanical works.

Link (1841) proposed the genus Ngllggg_from collections at the
Berlin Gardens and Smith (1841) applied the name Platyloma to the same
group of plants from the collections at the Kew Gardens. Smith's name
which was published in August of 1841 seems to have preceeded that of
Link. Tryon (1957) mentioned that in the British Museum's copy of
Link's work, it was issued between September 3 and 10, 1841.

Copeland (1947) in the figgggg Filicum recognized the genus Pellaea
as a natural one although he remarked that the affinities of the group
did not entirely support his view.

A committee on nomenclature for Pteridophytes reported a unanimous

vote to conserve Pellaea and the International Code adopted by the

al-

5
8th Congress at Paris, 1954, included Pellaea among the genera to be
conserved (Tryon, 1957).

Tryon (1957) stated some problems that existed in typifying the
Cheilanthoid group of ferns. She considered the section Pellaea to be
a restricted but natural group that was based on vegetative morphology
such as nearly glabrous, imparipinnate blade and free venation, and on
the continuous marginal indusium and terminal sori on discrete vein
ends.

Tryon and Britton (1958) considered Pellaea to belong to the tribe
Cheilantheae of the family Polypodiaceae: while Nayar (1963a) presented
us with a glimpse of how confused the state of the art was concerning
the genus Cheilanthes.

Cheilanthes is included by many pteridologists
(Christensen,1938; Capeland, 1947 and Diel, 1902) in the
pteroid phylum, but often regarded as representing a line
of evolution separate from that of Pteris and related ferns.
Bower (1926-28) has separated Cheilanthes and its allies
from the Pteroids, designating them a "Gymnogrammoid fern“
and suggesting for them an origin from the primitive Super-
filiciales: the Cheilanthoid ferns are regarded as showing
much similarity to the Schizaeaceae. Co eland (1947) and
more recently Pichi-Sermolli (1957, 1960 support the possible
Schizaeoid ancestry of Cheilanthes. According to Copeland,
Hemionites and Pityrogramma are derived from the Cheilanthoid
ferns,“5n chium is a clbse relative and Actiniopteris
(a genus regaraed as a Pteroid derivative by most other
pteridologists) is a variant of the group. On the other
hand, Christensen (1938), Ching (1940) and Alston (1956)
regard the majority of the Gymnogrammoid ferns, including
Cheilanthes, as related to the Pteroid phylum. According
Fo Ching, Ehe Sinopteridaceae (which includes Cheilanthes
and On chium) are Pteroid derivatives and these in turn
have 9 ven origin to the Gymnogrammaceae (the Central
Group of Gymnogrammoids' of Bower) and Adiantum, Holttum
(1947, 1949 and 1954) associates the Gymnogrammoid ferns
with the Vittarioids in the family Adiantaceae, phy-
letically separate from the Pteroids, and regards them
as derived from the Osmundaceae-Schizaeaceae group. The
association of the Vittarioid ferns and Adiantum with the
Gymnogrammoids is supported by Pichi-Sermolli, as according

6

to him "the Gymnogrammoid, Cheilanthoid, Adianthoid and

Vittarioid ferns may be held to represent phyletic lines

which branched off early from a common stock (Pichi-

Sermolli, 1957), viz. ferns like the present Schizaeaceae."

The next page represents the taxonomic scheme of Pichi-Sermolli
(jN_Jermy, 1973).

Knobloch and Volz (1964) expressed concern regarding the separation
of the three genera as there are few if any naturally occurring,
exclusive characteristics that can be used to differentiate the repre-
sentatives of Cheilanthes, Notholaena and Pellaea.

Knobloch (personal correspondence, April 14, 1975) stated,

“. . . until more definite studies are made, the only distinctions I

know of is that Cheilanthes and Notholaena are hairy, scaly or both on

 

the leaves with the leaf margins scarcely enrolled in Notholaena and

fully enrolled in Cheilanthes. Pellaea has enrolled leaf margins but

 

the plant's leaves are generally free of scales or hairs, the adoption
of such a definition would, of course, necessitate moving a number of
species about, out of one genus and into another genus."

Based on these introductory remarks, Rolla Tryon (1956) has stated
the problem most accurately.

It is not likely that an adequate classification of the
genera of the Cheilantheae; Cheilanthes, Notholaena, Pellaea,
Dor‘opteris and related smaller genera, can be achieved*
wit out a previous knowledge of the species concerned . . .
It seems that the basic problem will be to determine lines
of evolution so that the meaning of characters is sufficiently
clear, which characters are of generic value, which are con-
vergent and which are only of specific expression . . . The
uncertainty of the definition of Notholaena is not all of
the difficulty, for if Cheilanthes and Pellaea were well
defined, the task might be more certain, But the problems in
those genera are in their own way, as perplexing as those in
Notholaena.

 

 

 

7
Having briefly reviewed the classification schemes employed in
treatments of the "Cheilanthoid ferns," it is appropriate now to mention
previous researches in morphological, ecological, physiological, dis-
tributional, genetical and cytological and evolutionary areas, limiting

our review to what is known in Cheilanthes, Notholaena and Pellaea.

TABLE 1. Classification of the Filicopsida.

 

   
  

Prinfilicidu

  

  
     

   
   
   
   
   
 

Iotryonteridalea
Ali-Whit!
I
Suuroptedhles We.
Ophioglossidae Ophioglossales Ophioglosnceae
Psaroniaceae
Ang opteridaceae
Harntiidae Marattiales Marattiacea
naeaceae
hulfussiaceae
Osmndidae Osmndales Osmndacue
Senftenberqiaceae
Klukiaceae
Schizaeales T skyaceae
Acrosticopteridaceae u
Schizaeaceae
Pteridaceae
Negripteridaceae
Sinopteridaceae
togr
Pteridales Parkeriaceae
ogramceae
Ad antaceae
Vittariaceae
Dicksoniaceae
Dicksoniales Dennsuedtiaceae
Li nasaeaceae
Davallieceae
Davalliales Oleandraceae
Hymenophyl 1a 1 as Nymenophyl laceae
Fili id: Filicidae Lone-ales Loxsmceae .
Gleicheniales 21mm? , ;
Lophosoriaoele
Cyatheales Cyntheaceae '
Aspidilles
Blechnales
Natoniales '
Polypodiales

Plagiogyriales

WWI-
lopsidlles

Nanileales

    
 

LITERATURE REVIEW

A. MORPHOLOGICAL
Maxon (1918) contributed a key for some of the lip ferns
(Cheilanthes) of the southwestern parts of the United States. Specifi-

 

cally he was concerned with: Cheilanthes myriophylla, g, Nootonii,
EN Covillei, g, villosa, g, Fendleri, g, Clevelandii and g, intertexta.

 

 

 

Of particular note and interest was that the habit of the rhizome was
used as the first key character.

Rolla Tryon (1938) expressed an interest in the forking of ferns
and collected over three hundred specimens that represented some twenty-

eight Species. One of the species collected was Pellaea atropurpurea

 

var. cristata Trelease, which was described as a plant that would exhibit
forked fronds in successive years. Forking is primarily a problem for
the cytologist and geneticist, stated Tryon, but gross observations can
shed some light on the phenomenon.

Hagner (1952b) established a system for treating the dichotomy of
the major vascular axes of leaves in living ferns, stating that they
exist in four distinguishable forms (excluding the Gleicheniacea).

Each type is named for the feature of the leaf which accounts for its

 

organization. Pellaea atropurpurea, N, rotundifolia and N, viridis are

 

mentioned as three of the representatives considered in the midribless

blade type. This is the commonest type found and can be characterized

9
as having regular or symmetrical dichotomy of the major veins, no midrib
present and with mature fronds like the juveniles.
Abeywickrama (1956) noted the occurrence of gemmae on Cheilanthes

thwaitesii and that the gemmae would germinate soon after separating

 

from the parent plant if they landed in a suitable environment (moist
soil).

General morphological characteristics of the rhizome, paleae,
leaves (rachis, stipe and pinnae), sporangia, indusium, spores, prothal-

lus and early juvenile leaves of the genus Cheilanthes are presented by

 

Nayar (1962a). In addition to the general characteristics of the genus,
the fbllowing taxa are treated morphologically: g, albomarginata, C,

bullosa, N, chrysgphylla, g, dalhousiae, g, farinosa, Q, mysurensis,

 

g, pteridioides, g, rufa, C.

tenuifolia and N9 thwaitesii. A key based

 

 

on morphological characteristics of the taxa is provided to identify the
species. The problematical nature of the genus is also pointed out.

Nayar (1963a) described ten species of Cheilanthes. He concluded

 

that the vascular cylinder was dictyostelic, and considering the rest of
morphological information, further concludes that there was a close

affinity of Cheilanthes with Hemionites and Doryopteris, and that the

 

 

Schizaeoid ferns seem like more probable ancestors of Cheilanthes than
the Pteroid or other groups of ferns.

Knobloch (1965) analyzed some species of Cheilanthes as to their

 

type of vernation. It was found that 11 species exhibited circinate
vernation and 18 species exhibited non-circinate vernation. Knobloch
concluded that the type of vernation possessed by each taxa was a fixed

genetic response and not changeable by environmental factors.

lO

Pellaea andromaedifolia (Kaulf.) Fee was first morphologically
described in 1824 and since then various forms of this Californian
species have received systematic recognition (Pray, 1968).

Knobloch (1966b) presented a preliminary review of the Spore number

and apogamy in the genus Cheilanthes. A review of the Species that had

 

been reported as apogamous was presented along with the spore number for
14 additional species. Knobloch (1969) described the Spore patterns of
32 taxa of Cheilanthes. It was noted that all taxa had radially
symmetrical spores and that seventeen taxa showed some degree of spore
abortion.

Hitt and Knobloch (1967) point out the complexity of past morpho-
logic and taxonomic considerations of the Cheilanthes eatonii, Q,
castanea and g, tomentosa complex. In an attempt to clarify this com-
plex, spore, gametophyte and various aspects of sporophyte morphology
(rhizome, rhizome scales, frond size, hairs and scales and sporangia)
were considered. Previously Knobloch (1966b, 1967) reported 9, eatonii
and g, castanea as 2n = 87 and g, tomentosa as 2n = 90. This indicates
that these species are triploids (Cheilanthes n = 29 and 30). From this

study it appears that.§N eatonii and g, castanea are more closely related

to one another than they are to £5 tomentosa.

B. ECOLOGICAL

Most of the Species of Cheilanthoid ferns grow in rocky habitats,
fer example, on ledges, crevices of cliffs, on talus slopes, at the base
of large rocks or in rocky ground.

They are especially abundant in areas where such habitats are

common and there is a dry period during part of the year. Species are

11
fewer or entirely absent in regions where it is dry most of the year
and in regions with cold or constantly wet climates (Tryon and Tryon,
15.Jermy, 1973).

Many species of the Cheilanthoid ferns have morphological character-
istics which are evidently adaptive to seasonally dry habitats. Hevly
(1963) concerned himself specifically with this subject. Some of the
adaptations that are found within the group include the following:
complex leaves with many small ultimate segments, or a compact lamina
architecture, a densely scaly, pubescent or ceraceous lamina indument,
very coriaceous blades, and an abscission zone in the stipe. Parallel
evolution has undoubtedly been frequent. Convergent evolution, as used
by Hevly (1959, 1963), means similarity among unrelated taxa.

Cheilanthes, Notholaena and Pellaea are related taxa, and the author

 

would prefer the use of the term "parallel evolution." Pellaea

andromaedifolia (Kaulf.) Fée and Notholaena parvifolia Tryon, each with

 

numerous, small coriaceous leaf segments; Cheilanthes scariosa (Sw.)
Presl and Saffordia induta Maxon, each with densely scaly lamina (Tryon
and Tryon, 19_Jermy, 1973).

Wherry (1920), while contributing ecologic information concerning
soil reactions of certain rock ferns, did mention Cheilanthes lanosa and
g; tomentosa plus Pellaea atropurpurea and N, glabella. Nherry concluded
that both species of’Ngllggg_were to be considered calcareous soil
plants with a moderate tolerance for acid reactions. For Cheilanthes
he concluded that the data was inadequate for evaluation.

Hayes (1924) mentioned a number of different culture methods for
Pellaea atropurpurea that were used for an examination of the sex organs

on the prothallia. She suggested that her findings (failure to produce

12
archegonia) indicated a possible adaptation to a xerophytic habit. She
also described the development of the Sporophytes on the gametophyte and
noted that the sori were produced in one year. Subsequent work by many
workers has shown that N, atropurpurea and many other ferns fail to
develop archegonial cells on the prothallus; this is an indication of
the apogamous condition. Large oil vacuoles were found in the prothal-
lus and sporophyte, with the younger leaves having more oil than the
mature leaves. The presence of bi-nucleate cells in a continuous layer
around the notch of the gametophyte tissue surrounding the growing sporo-
phyte was noted with the supposed function of increasing the nuclear
surface as an aid in metabolic processes (Hayes, 1924). Chromosome
counts of both gametophytes and Sporophytes were obtained with some dif-
ficulty, both counts were recorded as :40. It has been subsequently
determined that the gametophytic and sporophytic number in N,
atropurpurea is the same, namely 87.

Thomas Pray (1968) and others familiar with the species have
recognized its plasticity in response to the environment. The variety
.£!2£!§.D- C. Eaton and the variety gracilis Summers ex Farlow are exam-
ples of environmentally induced variants. Pray recognized, however, that
the variety pubescens D. C. Eaton was decidedly distinct. The variety
pubescens appears to be strictly a coastal ecotype occurring from San
Luis Obispo, California, south to Cedros Island off the coast. The dis-
tinctions are based on evidence of the vein pattern in fresh material of
the variety pubescens, lack of the vein pattern in andromaedifolia,
bipinnate leaves in variety pubescens and tri-pinnate leaves in the
typical variety and leaves of only 35 cm. in length in the typical form.

Based on the above and other criteria, Pray stated that the evidence was

13
sufficient to recognize the systematic position of the variety pubescens.
In Pray's (1968) opinion the varieties are comparable to good subspecies

in other groups.

C. PHYSIOLOGY

Tryon (1957) pointed out the remarkable tolerance to desiccation
that the spores and gametophytes of Pellaea have. As an example of this,
the research conducted by Pickett and Manuel (1925) was cited. Pickett
and Manuel (1925) carried out desiccation experiments with N, atropur-
£2£22.a"d N, glabella in which some plants were air-dried for nine and
some for 18% months. When watering was resumed some of the plants
became green and continued to grow. Five years later Pickett (1931)
examined the same cultures and 5 percent showed whole or partial recovery
when satisfactory growth conditions were restored.

With the appearance of more chemo-taxonomic studies present in the
literature and with the increase in acceptability and significance of
the data, it is a wonder that the article by Mathews (1945) concerning
the toxicity of Notholaena sinuata and N, sinuata var. cochisensis had
not been more widely accepted and cited in the literature, especially as
it related to the taxonomy of the sinuous cloak-fern complex. Mathews'
data on feeding the ferns to sheep and goats is conclusive. The results
were as follows: those animals fed a total of 4.5 to 8.4 pounds of N,
sinuata (Lag. ex Sw.) Kaulf. for 6 to 9 days showed no ill effects. The
animals fed from 1.8 to 6 pounds of N, sinuata var. cochisensis
(Goodding) Weath. for 2 to 3 days (feeding was stopped as toxic effects

were noticed) Showed marked toxic effects.

14

”In view of the fact that the two plants occur in the same soil
fbrmation, that one is toxic and the other is not and that the two plants
can be readily differentiated, the present classification is certainly
inadequate. The gulf between these two plants should provide sufficient
reason for classifying var. cochisensis as a Species rather than a
variety" (Mathews, 1945). The physiology of the two taxa is clearly
different as the plants utilize the same nutrients in different manners.

A good deal of physiological and biochemical work on ferns is now
underway in various laboratories throughout the world, but the Cheilan-

thoid ferns have not been extensively involved so far in this area.

D. GENETICS, CYTOLOGY AND EVOLUTION

Tryon and Britton (1958) contributed a paper on cytotaxonomic
studies in the fern genus Pellaea. This paper dealt with apogamy in
Ngllggg_and listed a number of species and their meiotic chromosome
numbers.

Knobloch and Britton (1963) established the somatic chromosome
number of Pellaea Wrightiana as 87 and stated that the probable parents
of this triploid hybrid (or backcross) were Pellaea longimucronata 2X
and Pellaea ternifolia 4X. A comparison of characteristics and ranges
was presented indicating areas of overlap in both morphology and range
between supposed parents and the hybrid.

Recognition of Pellaea longimucronata in the eastern Mohave desert,
California, was noted by Shreve and Wiggins (1964) and Pray (1967).
Earlier collections of this Species are in herbaria from the Providence
Mountains, California (Dunkle 4251. AHFA) and the New York Mountains,
California (Ferris and Bacigalupi, 8076, RSA). These reports were not

15
cited by either A. Tryon (1957) or Munz (1959). Pray (1967) reflects on
the fact that the eastern Mohave region also includes the eastern limits

of Pellaea mucronata (D. C. Eaton) D. C. Eaton and that many inter-

 

mediates exist between N, longimucronata and N, mucronata in that

 

region which are most likely hybrids.
Wagner (1965) described the hybrid origin of N, Wrightiana and

 

noted its variability and most obvious affinities with N, ternifolia

 

and N, lgggimucronata. N, Wrightiana is intermediate in characteristics

 

 

 

between N, longimucronata and N, ternifolia; Wagner (1965) stated that
the hybrid N, Wrightiana should be reinstated as a species as had been

 

done by Hooker.

Cytological and taxonomic studies were carried out by Manton, Roy
and Jarrett (1966) on living material of two African cytotypes,
Cheilanthes farinosa (Forsk.) Kaulf. and of one, as yet unnamed sexual
diploid of the same genus from northern India. It was found that the
Indian diploid would hybridize with one of the African cytotypes. The
authors recommend further exploration of living material from both con-
tinents before any decisions were made concerning the number of taxa
worthy of binomial treatment that are present in either flora.

The chromosome numbers of five species of Cheilanthes were analyzed
by Knobloch (1966a). Previous to this date only 16 of 180 (Copeland,
1947) species of Cheilanthes had been counted. Knobloch's study added

 

 

4 new counts and confirmed a fifth species. Cheilanthes Wrightii was

counted as a diploid of 58. Cheilanthes tomentosa, at meiotic meta-

 

phase had 90 units, indicating that the plant is a triploid hybrid.
Cheilanthes (Aspjdotis) californica was established as having a haploid

number of 30, and N, (Aspidotis) carlotta-halliae was given a number of

16

30 bivalents and 30 univalents, suggesting that it was a backcross of

 

EN carlotta-halliae with one of its parents. Cheilanthes carlotta-
halliae has been previously described as a hybrid of N, siliguosa and
g, californica by Wagner and Gilbert (1957).

A review of spore number and apogamy, as it was known to exist
within the genus Cheilanthes, was published by Knobloch (1966b).
Twenty-four Species were listed with their spore numbers and some
twenty species were mentioned as being apogamous.

The results of Knobloch (1967) on the chromosome numbers of
Cheilanthes, Notholaena, ngxgg_and Polypodium added pertinent data to
the literature concerning those genera.

The cytology of all known representatives of the genus Cheilanthes

 

described at the rank of subspecies and above from Europe and the
Canary Islands was done by Vida, Page, Walker and Reichstein (1970).
In all, ten taxa were examined.

Knobloch, Tai and Adangappuram (1975) added considerable more
information on chromosome counts in the Sinopteridaceae. Confirmatory,

corrective and one new count of the chromosome condition of Cheilanthes

 

and Aspidotis were included in the paper. It should be mentioned that
Knobloch g§_gl, (1975), found Pichi-Sermolli's classification system (jg_
Jermy, 1973) useful. Knobloch g§_gl, (1975), also mentioned that there
is not enough chromosomal or morphological data to evaluate the evolu-
tionary relationships in Cheilanthes.

The sinuous cloak-fern complex (Notholaena sinuata) has long been
a subject of intensive study because of its polymorphy. Until recently
little was known of this complex other than gross morphological char-

acters and those have not been well understood (Hevly, 1965). Anatomical

17
data was practically non-existent until Rolla Tryon (1956) noted the
presence of two vascular bundles in the stipes of the sinuous cloak
ferns. Considerable taxonomic confusion has existed concerning the
status of the N, sinuata complex and the names applied to them (Tryon,
1956). Weatherby (1943) largely resolved the issue by delimiting three

major taxa within the complex: sinuata, cochisensis and integerrima.

 

 

 

Another taxon of the N, sinuata complex is N, sinuata var. pruinosa

(Fée) Fourn. N, sinuata v. pruinosa was not recognized by Weatherby
(1943) but he suggested that it might be recognized as a distinct variety
of N, sinuata. Rolla Tryon (1956) did not recognize N, sinuata var.
pruinosa as distinct but rather synonomized it with N, sinuata var.
sinuata. Based on the anatomy and morphology of prothallia. pH toler-
ances, temperature tolerances for spore germination, light intensities
for growth, phosphate requirements, spore size, size of pinnae, stomatal
number, xylem trace of the stipe, palisade layer of pinnae, indument of
rhizome, indument of the pinnae, scales, spores per sporangium and range,
Hevly (1965) identified the following species: N, cochisensis, N, X
integerrima and N, sinuata. Notholaena sinuata was divided into two

 

subspecies, each composed of two varieties (subsp. sinuata, vars.

sinuata, robusta and subsp. madriensis, vars. madriensis, pruinosa).

 

Knobloch 33,21, (1973), based on cytological evidence, states that
all the taxa studied by him and treated as varieties in the sinuous
cloak fern complex should be elevated to specific rank. This differs

from Hevly's opinion stated above. Notholaena pruinosa Fee (chromosome

 

number 2n . 87) is again elevated to species rank because it does not
seem logical that a presumed hybrid (N, pruinosa) could be a variety of

another presumed hybrid (N, sinuata var. sinuata, chromosome number

18
Zn . 87). Notholaena integerrima Hook. (chromosome number 2n = 87) is
presumably a hybrid although usually listed as a variety of N, sinuata,
but Knobloch discarded precedent for the same reasons as stated above
for this taxa also.
Apogamy as it occurred in Notholaena (Nothochlaena) distans R.

Br. was first reported by Berggren in 1888, while Goebel (1905) was the
first to report the existence of apogamy in the genus Pellaea, working

with Pellaea nivea (Poir) Prantl (now called Notholaena nivea (Poir)

 

Desv. var. fli!22)- Helena Woronin (1908) observed apogamy in Pellaea
flavens (Sw.) C. Chr. (Notholaena nivea flava), N, 3323 g (Gill.)
Prantl, Notholaena (Nothochlaena) sinuata (Lag. ex Sw.) Kaulf., and
Notholaena (Nothochlaena) eckloniana Kunze, and Steil (1911) recorded a

preliminary note on the apogamous development of Pellaea atropurpurea

 

Link.

Tryon (1968) attempted to understand the evolutionary role of the
apogamous mechanism in Pellaea, against a background of rapidly
increasing information on the frequency of the apogamous phenomenon in
the Pteridophyta. Ferns that exhibit the apogamous habit were consi-
dered to be of hybrid origin (Manton, 1950, 1961; Walker, 1966).
Apogamy in Pellaea is known to exist in six of the 15 species in the
section Pellaea (Tryon, 1968). She reported on three species of the
"light-stiped" group which represent a separate evolutionary line in the
section. Pellaea 93352, N, intermedia and N, andromaedifolia were
reported to be apogamous. The three species reported, however, were
unique in the occurrence of both sexual diploids and apogamous trip-
loids which have similar morphologies in each species. In each of the

species reported by Tryon she stated that each sexual diploid farm has

19
probably served as a parent in the cross that produced a
morphologically similar triploid. Tryon (1968) further stated a number
of possibilities as to the other parent. Comparisons were also made of
epidermal cell size, stomatal guard cell numbers, geographic distribu-
tion and spore size of the sexual diploids and apogamous triploids.
All three Species are triploids and are similar to the classic example

of apogamy as reported by Manton (1950) for Pellaea atropurpurea and

 

also reported by Tryon and Britton (1958) for N, sagittata.

E. DISTRIBUTIONAL NOTES

Alice Tryon (1957) published a major work entitled ”A Revision of
the Fern Genus Pellaea section Pellaea.“ The entities included in this
review numbered 15 species and 5 varieties. A note concerning specia-
tion processes was mentioned whereby apomixis, polyploidy and
hybridization had influenced speciation in N, glabella, N, sagittata

and N, ovata. The series related to N, ternifolia appeared to Tryon to

 

have evolved through gradual quantitative differentiation and through
isolation of the resulting populations.

The southwestern United States and adjacent Mexico were mentioned
as the most probable centers of dispersal for Cheilanthes, Notholaena
and Pellaea based on the fact that all the species described except N,
Breweri and N, glabella either converged on the above area or seemed to
be derivatives of those species that did.

Tryon and Britton (1958) note that the “diploids Pellaea Breweri
and N, glabella var. occidentalis are closely allied morphologically
and in several characters the two resemble some species of Cheilanthes

which occur within the same general geographical range."

20
Hevly (1965) contributed distributional information concerning the

Notholaena sinuata complex, while geographical data was contributed by

 

Wagner g§_gl, (1965) concerning Pellaea glabella var. glabella.

 

In 1967 Pray contributed some additional material as it related to
the distribution of American Cheilanthoid ferns. New collection sites
were added for various species and an attempt was made to bring the dis-
tributional records up to date.

Pray (1968), in his paper on Pellaea andromaedifolia, contributed

 

distributional notes and ecologic relationships for Pellaea
andromaedifolia and its valid varieties, plus N, mucronata, N,

longimucronata and N, intermedia.

 

Tryon and Tryon (1N_Jermy, 1973) discussed the geography, spores
and evolutionary relationships in the Cheilanthoid ferns while synthe-
sizing past research information as it related to evolutionary
relationships within the group. The concentration of the Cheilanthoid
fern species has been shown to occur in six major geographic areas
(Mexico, Andean, Australian, Brazilian, African and Sino-Himalayan)
where 282 of the 325 species occur. Nearly one-third (104 species) of
the Cheilanthoid ferns grow in the Mexican region. The authors have
also pointed out the distinctiveness of each region and have shown that
three-quarters or more of the species in one region do not grow in
another, with the exception of the Andean region which does share
several species with the Mexican and Brazilian regions. The American
Cheilanthoid species are almost completely different from the species of

the Old World with only Cheilanthes farinosa (Forsk.) Kaulf. and

 

Doryopteris concolor (Langsd. and Frisch) Kuhn. having amphiatlantic

ranges.

.«T‘

21

Nearly all well-defined species groups have their
species wholly concentrated in a single region, or a few
may extend into other regions. Examples in Notholaena
(Tryon, 1956) are the Notholaena geraniifolia Heath. group
(including N. venusta Brade, N, erio hora Fee, and N,

o azensis Tauh.) Brazilian except ior the occurrence
0? N. eriophora in the northern Andean region and the
Notholaena s uamosa (Hook. and Grev.) Lowe group (includ-
ing N. eruviana Desv., N. arqujpensis Maxon and N,
lonchophylla lryon) wholTy Andean. ’The Cheilanthes
ar entea (Gmel.) Kze. group (including, among others,

. uc ouxii (Christ) C. Chr. and N, ni hobola C. Chr.)
is Sino-Rimalayan, except for 9, ar entea which occurs
north eastward on the mainland ana to Japan. Speciation
in these groups may have been relatively recent; however,
they do provide evidence of the major geographic regions
as centers of evolution (Tryon and Tryon, jg_Jermy, 1973).

 

 

 

 

Wiggins (1973) added geographical and descriptive data on three

rare Cheilanthoid ferns (Cheilanthes viscida Davenp., E, peninsularis

 

Maxon and Notholaena peninsularis Maxon and Weatherby) from Baja

Califbrnia, Mexico.

F. ANATOMICAL, OTHER THAN RHIZOME

White (1963) stated that Notholaena sinuata had root tracheary
elements which appeared to be vessel members, but because true perfora-
tions in the end plates had not been experimentally demonstrated,
White referred to them as ”presumptive vessel members.“ Because of the
presence of vessel members in Pteridium aquilinum and possibly Woodsia
ilvensis, both of which occur in dry habitats, White thought it reason-
able that the character might be associated with the xerophytic habit.
He also checked Species typical of dry areas, including representatives
of the genera Cheilanthes and Pellaea. Unfortunately he does not name
the species examined, other than N, sinuata. Because of the presence
of apparent vessel members in Notholaena sinuata and Woodsia ilvensis,

and the taxonomic position of these species, White stated that,

22
'. . . it is possible that the sporadic occurrence of this cell type is
still to be found within other Species, genera and even families of
ferns." He also stated that due to the infrequent occurrence, in a sur-
vey of over 200 species, it is not probable that vessel members will
ever be found as commonplace structures.

Knobloch and Volz (1964) contributed more detailed studies on the
leaf blade anatomy of thirty-five species of Cheilanthes. The xerophytic
or near xerophytic habit was again pointed out and certain adaptations
to it. It was also reiterated that a great deal more descriptive
research of the Cheilanthes genus was needed before a proper perSpective
on species and Species relationships could be attained.

Knobloch and Volz (1968) once again added considerable anatomical
infbrmation concerning the genus Cheilanthes with their paper on the
anatomy of the stipes and rachises. Thirty-two Species were described
and compared with each other and to the species in the published litera-
ture. A statement to the effect that “. . . we found it surprising
that there were so many different patterns in the stipe and rachis,
going way beyond what had previously been reported. It would seem that
the multitude of axis conditions makes it impossible at this time to
characterize the genus by the anatomy of its aerial axis alone.“

Payne and Patterson (1973) published an interesting paper on the
presence of hypodermal layers in fern leaves. Within the family
Cheilanthaceae the following species were investigated: Adiantopsis
radiata, Anogramma lgptophylla, Anopteris hexagona, Bommeria hispida,
Cheilanthes alabamensis, g, gracillima, Coniogramme japonica,
ngptogramma acrostichoides, ngxgg.cordifolia and Pellaea glabella.
From these, only Coniogramme japonica was found to have a hypodermis.

23
The authors stated that the presence or absence of the hypodermal layer
may be useful fbr assessment of relative speciation and of evolutionary

relationships.

G. RHIZOME ANATOMY

Jeffrey (1902) mentioned that he had examined the rhizomes of
plants from a number of Polypodiaceous species, including some in the
genus Pellaea. However, the Species he utilized were not mentioned.
Jeffrey stated that the young central cylinder of the rhizome was
throughout a concentric fibro-vascular tube with foliar lacunae.

Gwynne-Vaughan (1903) stated that a true solenostele was not of
very general occurrence, although it was found in several different
genera, including Pellaea. He also mentioned that a transitional type
of stele, related to the solenostele could be found in Pellaea,
Notholaena and Cheilanthes. Pellaea atropurpurea and N, falcata were
described as having creeping, more or less dorsiventral rhizomes that

were typical solenosteles. Notholaena Marantae and Pellaea rotundifolia

 

were said to specifically possess a transitional type of stele.

Cheilanthes lendigera and N, microphylla were described as having an

aberrant fbrm of solenostely. The rhizome of Pellaea cordata was

described as being dorsiventral with the leaves inserted in several rows.
Tansley (1907) in describing dorsiventral types of dictyosteles

and the slight difference between them and dorsiventral solenosteles.

mentioned the genera Notholaena and Pellaea. N, Marantae and N,

rotundifolia were illustrated and mentioned as in Gwynne-Vaughan (1903).

Cheilanthes lendigera and g, microphylla were mentioned as being

“closer” to a solenostele, and it is interpreted that these species

were described in Gwynne-Vaughan's context of being “transitional.”

24

Tansley (1908) used Notholaena sinuata (Nothochlaena sinuata) to
illustrate the "Ontogenetic evolution of dictyostely through solenostely
from the Lindsaya-type (amphiphloic protostely) by the development of
ground tissue pockets which are from the first in connection to form a
pith . . . within the internal phloem, and the subsequent overlapping of
successive leaf gaps." Tansley inferred that in the mature condition,
Notholaena sinuata was a dictyostele.

Marsh (1914) contributed the first major paper concerning the

rhizome anatomy of Cheilanthes and Pellaea. "The stelar anatomy of

 

Cheilanthes and Pellaea is of interest in that each genus contains both

 

solenostelic and dictyostelic forms, together with others that are

intermediate between these types." Cheilanthes Fendleri was described

 

(Marsh, 1914) as having leaf gaps that were long, but failed to overlap,

hence it was a solenostele. Cheilanthes gracillima and Cheilanthes Feei

 

(as lanuginosa) were interpreted as being transitional in nature because
portions of their rhizomes included areas where two leaf gaps overlap,
while the greater portion of the rhizome was a solenostele.

Cheilanthes persica was described (Marsh, 1914) as a true dictyo-
stele, Pellaea falcata, a simple solenostele, while once more, N,

rotundifolia and N, andromaedifolia were described as transitional.

 

Marsh also started to shed some light on the anatomical problems of the
rhizomes which will be encountered when she stated, “The Ngllggg_
andromaedifolia which I examined may perhaps have been older material
than that used by Gwynne-Vaughan, for though it showed a dorsiventral
dictyostele. its structure was more complicated than that which he
describes." Mention was made of a close correlation between stelar

structure and the amount and arrangement of the wood within the stele.

25
Marsh (1914) also mentioned that the total number of "sieve tubes" was
very small and that there was no observable differentiation into proto-
phloem and metaphloem.
Posthumus (1924) while discussing principles of stelar morphology

and reviewing the work of previous investigators mentioned Cheilanthes,

 

Notholaena and Pellaea. In his review of stelar anatomy he lists:
Cheilanthes microphylla (dorsiventral solenostele), g, Nggl_(as Q,
lanuginosa, dorsiventral dictyostele), Q, gracillima (dictyostele
transitional to solenostele), N, lendigera (dorsiventral solenostele),
£9 persica (radial dictyostele), N, Fendleri (dorsiventral solenostele),
Notholaena gNNgg_(as ferruginea, dorsiventral dictyostele), N, Marantae
(dorsiventral dictyostele), N, sinuata (solenostele), N, trichomanoides
(dorsiventral solenostele), Pellaea falcata (dorsiventral solenostele),
N, rotundifolia (dorsiventral dictyostele), N, andromaedifolia (dorsi-

ventral dictyostele), N, atropurpurea (dorsiventral dictyostele), and

 

N, cordata (dorsiventral dictyostele). Mention was also made in many
instances as to the growth habit, i.e., erect, creeping with long inter-
nodes, etc. Posthumus also mentioned the type of leaf trace that was
present in many species.

In 1924, May Williams contributed a rather extensive paper on
Cheilanthes tenuifolia. The rhizome of this taxon was described as
being a dictyostele according to Gwynne-Vaughan's definition.

Of particular Significance in the interpretation of rhizome struc-
ture is the work of Hevly (1963). “The Cheilanthoid ferns, when grown
in greenhouses or transplanted to cooler, more moist regions such as
the Puget Sound area of Washington State, retain their typical growth

habit and associated anatomical and morphological alterations.

26
Variation in degree of structural change is not particularly noticeable,
indicating that in Cheilanthoid ferns these modifications are geneti-
cally fixed'I (Hevly, 1963). Xerophytic modifications are apparent
including: impregnation of the cell walls of the epidermis, cortex and
stele with suberin and lignin, and various epidermal appendages that are
found on the rhizomes and the fronds.

Nayar (1963a) contributed morphological descriptions of ten Species
of Cheilanthes including the rhizome, leaves, Sporangia, spores, pro-
thallia and juvenile Sporophytes. All the rhizomes of the investigated
taxa were considered to be dictyostelic (Nayar, 1963a).

Ogura (1973) noted that many authors point out two factors involved
in the formation of a dictyostele: (l) the dictyostele could be formed
as a result of the elongation of leaf gaps; and (2) from the shortening
of the internodes, so that the stem with closely arranged leaves would
usually show a dictyostele, whereas those plants with long internodes
would show a solenostele. In species such as Adiantum pedatum and
Cibotium barometz, a portion of the rhizome that has long internodes is
solenostelic, while another portion of the same rhizome with short inter-
nodes is dictyostelic. Notholaena and Pellaea rhizomes were Specif-
ically mentioned as representatives illustrating such an intermediate
type of solenostele and dictyostele.

McCulloch, V012 and Knobloch (1974) reported on the rhizome anatomy
of twenty-six taxa in the genus Cheilanthes. A review of some of the
pertinent literature as it related to steles and the genus was discussed
along with an anatomical analysis of the species. Twenty species were
described as solenosteles while six were described as transitional

steles.

27
H. REVIEW OF STELAR DEFINITION

Protostely is a primitive condition, as it is found in all
primitive vascular plant stems (except the mature stems in the
Equisetales), in juvenile plants of the Filicales, in some fossil ferns
and in the adult form of some species of the Filicales (Jeffrey, 1902;
Thompson, 1920). Any departure from the simple protostele is commonly
regarded as a derived condition (Foster and Gifford, 1959).

Wardlaw (1945) stated that, "The shoot stele, whether it was
protostelic, solenostelic or dictyostelic, consisted initially of an
uninterrupted solid or hollow subconical mass of tissue and that during
the subsequent differentiation of the tissues of the leaf Shoot system,
distinct changes took place and internal structural features of con-
siderable complexity could be produced."

The term protostely, as such, can be found in the literature by
several definitions and in many variations.

Worsdell (1902) described a protostele as being a central mass of
wood (xylem), surrounded by a zone of bast (phloem), ". . . this in turn
having been derived from the primitive conductive tissues of the sporo-
phyte stem of some bryophytic ancestor."

Gwynne-Vaughan (1903) described a protostele in Nygodium to be the
continuing of the central xylem mass not being interrupted by the subsi-
dence of the external tissues, either cortical or vascular, at the
departure of the leaf trace. He stated that this has not yet been
fbund in the Polypodiaceae.

Schoute (jg_Verdoorn, 1938) described a protostele as a monostele

with a peripheral phloem and a central mass of xylem.

28

Foster and Gifford (1959) stated that a protostele was a solid
cylinder of xylem in the stem surrounded by phloem.

The protostele as described by Esau (1965) was a solid column of
vascular tissue enclosing no pith.

Ogura (1972) described the protostele as a ectophloic concentric
vascular bundle, enclosed by an endodermal layer. He defined fourteen
types of protosteles: a) primitive protostele; a small protostele that
consists of a few tracheids and phloem elements (the primitive proto-
stele of Ogura is the same as the haplostele as described by Fahn, 1967,
1974); b) typical protostele; the circular concentric stele is enclosed
by an endodermis and can be distinguished from (a) by its larger size;
c) stellate protostele; the xylem is stellate in cross section and on
the tip of each arm can be found exarch protoxylem; d) Asteroxylon type;
xylem is stellate, but the form and number of the xylem arms are irregu-
lar and part of the arm can separate or fuse with each other;

e) Arachnoxylon type: this is similar to (d), the only difference is in
the existence of a parenchyma island near the external and of each xylem
arm; f) protostele with mixed pith; this type has parenchyma cells mixed
among the tracheids, this was called a mixed pith by Brebner (1902);

g) medullated protostele; this is similar to (f) except that in the
center of the xylem there is a mass of parenchyma; h) Lindsaea type,
originally the Lindsaya type of Tansley and Lulham (1902); this is an
amphiphloic form in which there is a phloem mass within the xylem;

i) radial type: a radial vascular bundle enclosed by an endodermis
layer: j) dorsiventral type; cross section of the stele would be flat-
tened, elliptical or band-shaped; k) Nycopodium type; a modified radial

protostele where the xylem is not truly radial but more or less

29

irregularly radial or band-Shaped, being sometimes arranged in parallel
bands in cross section; 1) Osmunda type; the xylem ring is interrupted
radially by parenchyma in many parts, but the phloem and endodermal
layers are situated continuously on the external side of the phloem;

m) Hymenophyllaceae type; the typical protostele becomes through dorsi-
ventrality and reduction, dorsiventral and further subcollateral then
collateral and lastly, extremely reduced; n) reduced protostele; the
xylem and phloem are so extremely reduced that the stele consists of a
few tracheids and sieve tubes.

Fahn (1967, 1974) considered a protostele to be a solid cylinder
of xylem surrounded by phloem. He described three types of protosteles:
a) haplostele; the xylem appears to be more or less circular in cross
section (primitive protostele of Ogura, 1972); b) actinostele; the xylem
is stellate in cross section; and c) plectostele; the xylem is split
into longitudinal plates, some of which are joined and others separated.

It appears that one can be either a "lumper' or a "splitter“ when
it comes to describing the protostele condition and as we shall see
subsequently, other stelar conditions as well. The question of whether
to lump or split, then is not confined necessarily to the field of
taxonomy, but is also a problem in anatomy. This raises numerous ques-
tions when documentation of anatomical infbrmation is needed,
particularly at the species level.

The following taxa have been recorded as having a particular type
of protostele:

PRIMITIVE PROTOSTELE (Ogura, 1972) or HAPLOSTELE (Fahn, 1967, 1974):
Gosslingia (Gwynne-Vaughan, 1903), Nggggg.(6wynne-Vaughan, 1903),

Horneophygon (Ogura, 1972), Rhygia major (Gwynne-Vaughan, 1903), Rhynia

30
(Gwynne-Vaughan, 1903; Ogura, 1972; Fahn, 1967, 1974), Rhyneaceae
(Schoute, 1938) and Selaginella (Fahn, 1974).
TYPICAL PROTOSTELE (Ogura, 1972) or HAPLOSTELE (Fahn, 1967, 1974):
fggllg.(Bower, 1923; Bierhorst, 1971), Botryopteris (Ogura, 1972),
Botryopteris cylindrica (Bower, 1923), Cheiropleuria (Posthumus, 1924;
Bower, 1928; Ogura, 1972), Hymenophyllaceae, Lygodium, Gleichenia,
Botryopteris (Worsdell, 1902), Cheiropleuria bicuspis (Posthumus, 1936),
Cochlidium seminudum (Posthumus, 1936), Gleicheniaceae (Ogura, 1972),
Gleichenia flabellata, EN linearis (Bower, 1923), Gleichenia $212227
ng§N2_(Alston, 1958), Hecistopteris 229112 (Bower, 1923), Lepidodendron
esnotense, N, pettycurense, N, saalfeldense (Ogura, 1972), Macroglena
meifolia (Ogura, 1972), Monoggamme (Bower, 1923), Psilotum (Schoute,
1938), Salvinia (Bierhorst, 1971), Selaginella selaginoides (Fahn, 1967;
Ogura, 1972), Selenodesmium (Ogura, 1972), Tmesipteris (Schoute, 1938),
Tubicaulis (Ogura, 1972), Vandenboschia scandens (Ogura, 1972).
PROTOSTELE WITH MIXED PITH: Ankyropteris (Bower, 1923), Cheiropleuria
(Bower, 1928), Diaplolabis (Ogura, 1972), Gleichenia (Bower, 1923),
Nepidodendron intermedium, N, Selaginoides (Ogura, 1972), Nygodium
(Bower, 1923), Mecodium demissum (Ogura, 1972), Metaclepsydropsis
(Ogura, 1972), Thamnopteris Kidstoni (Ogura, 1972) and Vandenboschia
radicans (Ogura, 1972).
MEDULLATED (Ogura, 1972) or ECTOPHLOIC SIPHONOSTELE WITHOUT LEAF GAPS
(Sporne, 1962): Ankyropteris (Ogura, 1972), Asterochlaena (Ogura, 1972),
Bothrodendron NNyNg_(Ogura, 1972), Lepidodendron aculeatum, N, N35:
courtii, N, obovatum (Ogura, 1972), Lepidophloios fuliginosus (Ogura,
1972), Osmundites dunlopi (Ogura, 1972), Platyzoma microphyllum (Ogura,
1972), Schizaea spinosa (Ogura, 1972), Sigillaria (Ogura, 1972).

31
STELLATE (Ogura, 1972) or ACTINOSTELE (Fahn, 1967, 1974): Psilophyton

 

(Fahn, 1967, 1974; Ogura, 1972), Sphenophyllum (Ogura, 1972).
ASTEROXYLON: Asteroxylon (Ogura, 1972; Schoute, 1938), Mesoneuron
(Ogura, 1972), Schizopodium (Ogura, 1972), Stenokoleos (Ogura, 1972).

 

ARACHNOXYLON: Arachnoxylon (Ogura, 1972), Asteropteris (Ogura, 1972),
Iridopteris (Ogura, 1972), Reimannia (Ogura, 1972).

DORSIVENTRAL: Nymengphyllaceae (Ogura, 1972), Mecodium scabrum (Ogura,
1972), Selaginella species (Schoute, 1938), Selaginella involiens, §,
Karsteniana, §, sergens (Ogura, 1972) and Trichomanes reniforme (Ogura,
1972).

HYMENOPHYLLACEAE TYPE: Crepidomanes (Ogura, 1950), Crepidgpteris

(Ogura, 1972), Didymoglossum giesenhagenii, Q, hymenoides, N, labiatum

 

(Ogura, 1972), Gonocormus (Ogura, 1950), Hymenophyllum (Ogura, 1950),
Nymgnophyllum barbata (Ogura, 1972), Lecanium membranaceum (Ogura, 1972),
Mecodium (Ogura, 1950), Meringium E25221 blandum (Ogura, 1950),
Pleuromanes (Ogura, 1950), Scledodesmium (Ogura, 1950) and Vandenboschia

(Ogura, 1950, 1972).

 

LINDSAEA: Davallia Nymenophylloides, N. Parkeri, _D_. 53331;, N. Naggi-
jNNjN_(Gwynne-Vaughan, 1903), Lindsaea (Bower, 1928; Ogura, 1972),
Lindsaea clavata, N, trapeziformis (Bower, 1928), N, Blumeana, N,
cuneata, N, cultrata, N, composita, N, guianensis, N, hymenophylloides,
N, 1.3.1221: N. linearis, N. microphylla, N. orbiculata, N, Parkerii,

N, reniformis, N, repens, N, rigida (Posthumus, 1936), Schizoloma

 

ensifolium (Posthumus, 1936), Stenoloma chusanum, §, clavatum, §,
retusum (Posthumus, 1936), Tapaenidum (Posthumus, 1924; Bower, 1928),
Tapeinidium Brooksii, I, moluccanum and I, pinnatum (Posthumus, 1936).
RADIAL: Nycopodium (in some young species, Ogura, 1972).

1.1

u

.01
,.

1’“:

.‘I

 

32
LYCOPODIUM: Lycopodium (Schoute, 1938; Ogura, 1972).

 

OSMUNDA (Ogura, 1972) or ECTOPHLOIC SIPHONOSTELE (Foster and Gifford,
1959): Q§E2222.(B°"er’ 1923; Foster and Gifford, 1959; Ogura, 1972).
REDUCED: ‘Nggllg_(Bierhorst, 1971), Isoetaceae (Ogura, 1972) and
Salviniaceae (Bierhorst, 1972; Ogura, 1972).

 

The development of the solenostele and/or dictyostele from a
primitive protostele is well documented in the literature. A fuller
explanation of this will be made under the heading "Ontogeny of the
Stele."

"In short, it (the concept) has been described by many authors that
the solenostele is derived from the protostele through the formation of
pith, internal phloem and internal endodermis“ (Ogura, 1963).

If we consider that the solenostele is derived from a protostele,
then the origin of the pith and other internal tissues must be accounted
for. There are two theories as to the origin of the pith, i.e. the
"extrastelar" and "intrastelar." According to Jeffrey (1897, 1902,
1910) medulation could be derived by the invagination of the cortical
tissue into the pith; more Simply stated the pith would be homologous
with the cortex.

According to the "intrastelar" theory, however, the pith could have
originated within the stele itself and, therefore, the pith and cortex
would not be homologous.

The "intrastelar" theory has been supported (since Tansley and
Chick, 1900) by many authors, including Farmer and Hill (1902), Tansley
and Lulham (1905), Charles (1911), Lang (1913-15), Gwynne-Vaughan (1914)
and Thompson (1920). Thompson (1920) found that the pith did arise

jg situ by the differentiation of procambial cells as reported in

‘u

\..

 

 

33
Schizaea malaccana, §, dichotoma, Gleichenia pectinata, Loxosoma
Cunninghamii, Achrosticum gNNgNm.and Lindsaya adiantifolia.

As stated before, in most primitive vascular plants the stele of
the youngest portion is a primitive protostele (Jeffrey, 1902; Thompson,
1920, Ogura, 1972). If we trace the stele from the youngest part
basally, the stele widens in a conical fashion and the parenchyma mass
appears within the xylem (Ogura, 1972). This is the first step in pith
fbrmation and it should be noted that there is no direct connection with
the cortex and that there is no gap at the node (Ogura, 1972). It is in
older tissue that the pith and cortex connect with each other through
the leaf gap (Ogura, 1972). During ontogenetical development, the paren-
chyma of the cortex appears to ”enter" the xylem from the leaf gap
downwards as if it were a “pocket” (Boodle, 1903; Ogura, 1972). The
pocket can be seen in the phloem as well as the endodermis and has been
observed by Boodle (1903) and Thompson (1920) in the Gleicheniaceae or
Schizaeaceae (Ogura, 1972).

“The pocket fermation seems to be favorable for the extrastelar
hypothesis, but the appearance of the internal tissues can be in a more
or less lower part of the pocket, and the connection of the external and
internal tissues seems to be rather secondary. Moreover, in the young
part of Acrostichum 2!!£!E.a"d Schizaea dichotoma, the internal endo-
dermis is enclosed within the pith in a spindle or 'endodermal island'”
(Thompson, 1920).

“This phenomenon may be also favorable for the intrastelar
hypothesis” (Ogura, 1972).

More support for the intrastelar origin of the pith can be found in
the existence of the mixed pith and medullated pith, as found in the

34

Osmundaceae, Ophioglossaceae, Coenopteridales and Lepidodendrom (Ogura,

 

1972). The existence of medullation in Lepidodendron is very clear, as
there are no leaf gaps, the medullated protostele could have been derived
from the typical protostele going through the stage of mixed pith (Ogura,
1972). Cells with tracheidal thickening among the pith have also been
reported in Schizaea (Tansley and Chick, 1900), Osmunda (Gwynne-Vaughan,
1914), Igggg.(5eward and Ford, 1903), Osumndites (Kidston and Gwynne-
Vaughan, 1910), Ophioglossaceae (Bower, 1911; Lang, 1912, 1913-15;
Vasisht, 1927; Nozu, 1956), Ankyropteris (Scott, 1912), Asterochlaena
(Stenzel, 1889) and Asterochlaenopsis (Sahni, 1930; Ogura, 1972).

The term siphonostele seems to be the most widely accepted term
for a stele with pith. We will subsequently find out, however, that
there are different terms being applied to the same or very similar
stelar conditions. A review of the concept of a siphonostele by
various authors follows.

Schoute (1938) defined a siphonostele as a medullated protostele
with an internal endodermis.

Foster and Gifford (1959) stated that a siphonostele was a stele
with pith.

Esau (1965) said that a siphonostele had a pith, and Fahn (1967,
1974) explained that a siphonostele was a condition where there was a
cylinder of pith within the xylem.

Ogura (1972) on the other hand does not use the term siphonostele
but seems to equate the term solenostele with it. He defined a soleno-
stele as one with a cylindrical stele with a central pith, which can
connect at the leaf gap with the cortex. The vascular bundle consists

of the xylem and external and internal phloem that are enclosed by the

35
external and internal endodermal layers (Ogura, 1972). There are not
more than two leaf gaps in a cross section (Ogura, 1972).

Gwynne-Vaughan (1903) does not use the term siphonostele.

Further confusion sets in when an analysis of the sub-categories of
the siphonostele concept are delineated.

Schoute (1938) described three types of siphonosteles: a) amphi-
phloic siphonostele; a siphonostele with a second phloem ring on the
inside of the xylem; b) solenostele; a siphonostele perforated by
scattered leaf gaps; c) dictyostele; a solenostele with more leaf or
other gaps, so as to show more than one interruption in any one trans-
verse section.

Foster and Gifford (1959) describe two sub-categories of siphono-
steles with one sub-category having two types: a) ectOphloic
siphonostele; having an external cylinder of phloem only; b) amphiphloic
siphonostele; having internal and external cylinders of phloem (also
endodermis), type 1) solenostele, without overlapping leaf gaps and
2) dictyostele, an amphiphloic tube of vascular tissue in which paren-
chymatous leaf gaps overlap.

Esau (1965) differentiated three sub-categories of a siphonostele:
a) ectophloic siphonostele; the phloem occurs only on the outer side of
the xylem cylinder; b) amphiphloic siphonostele or solenostele; phloem
differentiates on the inner side of the xylem as well as the outer side,
in its simplest form this type has no leaf gaps; c) dictyostele; large
leaf gaps that overlap to the extent that the vascular system appears
dissected into a net-like structure with each segment constituting a

concentric vascular bundle.

36

Fahn (1967, 1974) differentiates five sub-categories of
siphonosteles, with one sub-category having two types: a) ectophloic
siphonostele; the phloem surrounds the xylem externally; b) amphiphloic
siphonostele; where the phloem surrounds the xylem both externally
and internally and where the endodermis appears both outside, bordering
the cortex, and inside the vascular tissue on the border of the pith,

1) solenostele, an amphiphloic siphonostele in which the successive

leaf gaps are considerably distant, one from another, 2) dictyostele, an
amphiphloic siphonostele with overlapping gaps, i.e. that in which the
lower part of one gap is parallel with the upper part of another gap.

In this condition the vascular bundles are inter-connected to form a
cylindrical network and each bundle is of a concentric structure consist-
ing of a central strand of xylem surrounded by phloem. Individually the
bundles are termed meristeles, from an anatomical view these are
amphicribal bundles; c) eustele; collateral bundles, developed from the
ectophloic siphonostele; d) polycyclic stele; two or more concentric
cylinders of vascular tissue are present; e) polystelic; stems and roots
containing more than one stele.

The earliest reference to a solenostelic type of structure was made
in 1838 by Robert Brown who noted the presence of a complete ring of
'vasa scalariformia“ in Polypodium Horsfieldii R. Br. (Dipteris 5233
m, Reinw. ) .

It seems appropriate to introduce Gwynne-Vaughan's (1903) idea of
the solenostele and dictyostele at this point. Gwynne-Vaughan formu-
lated his concept in this fashion: a solenostele held an intermediate
position between a simple protostelic type and a more complicated farm,

the dictyostele. The dictyostele, a term first proposed by Brebner

v.

to:

Y;

 

 

37
(1902), was the tubular network of vascular tissue that arose by the
occurrence and overlapping of gaps (leaf?) in a solenostele.

Ogura (1972) has four sub-categories of solenosteles: a) typical
solenostele; an amphiphloic cylinder enclosed by both endodermal layers
with the stele radially constructed; b) dorsiventral solenostele;
similar to the former, but is different in its dorsiventral structure,
having leaf gaps situated mainly on the dorsal side of the stem;

c) ectophloic solenostele; the absence of the internal phloem (and endo-
dermis); d) Equisetum type; a ring of collateral bundles accompanied by
a peculiar endodermis layer.

The following taxa have been recorded as having some type of

solenostele:

TYPICAL SOLENOSTELE: Acrostichum (Bower, 1923), Adenophorus sarmentosus

 

(Wilson and Rickson, 1961), Adiantum pedatum, N, hisgidulum (Bower, 1928),

 

Adiantum (Fahn, 1967), Anemia (Bower, 1928; Ogura, 1972), Anemiorrhiza
(Bower, 1923), Anggramma subdigitatum (Posthumus, 1924, 1936),

 

Amphidesmium blechnoides (as Metaxya rostrata, Bower, 1928; Stevensen,

 

1974), Antrophytum plantagineum (Bower, 1928), Arthropteris (Bower, 1928;

 

Tindale, 1961), Aspleniopsis decipiens (Posthumus, 1936), Cheilanthes
aemula, N, angustifolia, N, Brandegii, N, castanea, N, Cooperae, N,
Covillei, N, Eatonii, N, Fendleri (probably misidentified, Bower, 1928),

N, gracillima, N, horridula, N, intertexta. N} lendigera, N, Lindhelmeri,
C. mexicana. N, myrioggylla, N, notholaenoides, NN Pringlei, N, tomen-

 

tosa, NN Wootonii, N, Wrightii (McCulloch gN_gl,, 1974), Christensenia
aesculifolia (Kaulfussia aesculifolia, Kuhn, 1889; Stevensen, 1974),

 

Craspedodictyum quinatum (Posthumus, 1924, 1936), Davallia hirsuta, N,
magginalis, N, sgeluncae, N, strigosa, N, platyphylla (Gwynne-Vaughan,

38
1903), Davallia (Prosaptia) contigua, N, dubia (Bower, 1928),

Dennstaedtia rubiginosa (as Dicksonia rubiginosa, Gwynne-Vaughan, 1903;

 

Stevensen, 1974), Dennstaedtia punctilobula (Morton and Neidorf, 1956),

 

Dennstaedtia Sp. (Bower, 1928), Dicksonia apiifolia, N, cicutaria, N,

 

 

scabra, N, Nunctiloba, N, davallioides (Gwynne—Vaughan, 1903), Dicranog-

 

teris pectinata (Ogura, 1972), Diellia falcata (Bower, 1928), Diglora

 

 

longifolia, N, schizocarpa, N, d'Urvillei (Posthumus, 1924, 1936),
Dipteris conjugata (Stevensen, 1974), N, novo-guineensis, N, Wallichii

 

(Posthumus, 1936), Digteris (Ogura, 1972), Doryopteris ludens

 

(Posthumus, 1924, 1936), Egenolfia gppendiculata (Posthumus, 1924, 1936),

 

Elaphoglossum latifolium (Bower, 1928), Gleichenia pectinata (Bower,

 

1923), Histiopteris incisa (Bower, 1928), Nymenophyllopsis (Ogura, 1972),

 

Hypolepis tenuifolia, N, millefolium, N, distans, N, regens (Gwynne-
Vaughan, 1903; Bower, 1928), Jamesonia imbricata (Gwynne-Vaughan, 1903;

 

Posthumus, 1936), N, scalaris (Posthumus, 1936), Leptolegia (Posthumus,
1924; Bower, 1928), Leucostegia immersa, N, Nallida (Posthumus, 1924,

 

1936), Lindsaya (Gwynne-Vaughan, 1903), Llavea cordifolia (Posthumus,
1924, 1936), Lonchitis aurita, N, DIE§!£2.(B°W9T: 1928), Loghosoria
(Bower, 1923; Ogura, 1972), NQN§QNN_(Gwynne-Vaughan, 1903; Bower, 1923),
Marsilea (Fahn, 1974), fl2£flfllé.(3°wer» 1923), NgNgNyg_(Bower, 1923;
Lucansky, 1974), Microlepia haflanensis (Nayar and Kaur, 1964a), NN
marginata, N, Nilosella, N, Wilfordii (Ogura, 1972), Microlegia
(Posthumus, 1924; Bower, 1928), Neocheiropteris palmatopedata (Posthumus,
1936), Notholaena sinuata (Posthumus, 1924), Odontosoria retusa, N,
aculeata (Posthumus, 1924; Bower, 1928), Paesia podophylla, N, Niggggg,
N, scaberula (Bower, 1928), Pellaea atrgpurpurea, N, fil£2££.(GWY""e'

Vaughan, 1903; Bower, 1928), Pityrogramma (Nayar, 1964), Polypodium

39
punctatum (Gwynne-Vaughan, 1903), Polygodium Sp. (Posthumus, 1936),
Mgrandifolia (Bower, 1928; Posthunus, 1936), N. _e_l_g_t_a_, N. M,
N. 191211;. N. scaberula (Gwynne-Vaughan, 1903), Pteridium aquilinum
(Bower, 1923, 1928), Saccoloma elegans (Stevensen, 1974), Stenochlaena
tenuifolia (Stevensen, 1974), Stromatopteris (Bower, 1928), Smgrama
alismaefolia (Posthumus, 1924, 1936), §_. alsinifolia, _S_. borneensis
(Bower, 1928), _S_. cartilagidens (Posthumus, 1924, 1936), Taenites blech-
11919.15. (Bower, 1928), Trismeria trifoliata (Posthumus, 1924; Bower, 1928)
and Vittaria (Bower, 1928).
DORSIVENTRAL SOLENOSTELE: Adiantum macrgahyllum, N. monochlagys, N.

Natens, N. Nedatum, N. petiolatum, N. Farleyense, N. Trapaeziforme
(Posthumus, 1924, 1936), Bolbitis (Nayar and Kaur, 1964b), Cheilanthes

 

Fendleri, N, lendigera, N. microghylla (Posthumus, 1936), Christiopteris
tricusgis (Posthumus, 1936), Davallia aculeata, N. hirsuta, N. hirta, D.

marginalis, N. Elatyghxlla, N. strigosa (Gwynne-Vaughan, 1903; Ogura
1972), Dennstaedtia adiantoides, N. consanguinea, N. cornuta, N. daval-

 

lioides, N. dissecta, N. ordinata, N. punctilobula, N. rubigniosa, N.
rufescens, N. m (Posthumus, 1924, 1936), N. cicutaria (Stevensen,
1974), Dicksonia adiantoides (Gwynne-Vaughan, 1903), N. apiifolia, N.
cicutaria, N. m N. Nunctiloba, N. davallioides (Gwynne-Vaughan,
1903; Ogura, 1972), Egenolfia (Nayar and Kaur, 1964b), Jamesonia
imbricata (Gwynne-Vaughan, 1903; Ogura, 1972), Histiopteris (Ogura,
1972), N. m (Posthumus, 1936), Nmolegis m, N. millefolium,
N. Lem N. punctata, N. tenuifolia (Gwynne-Vaughan, 1903; Posthunus,
1924, 1936; Ogura, 1972), Lindsaza £939.92. (Gwynne-Vaughan, 1903;
Posthumus, 1936), Ngmg sp. (Ogura, 1972), Marsilea Sp. (Ogura, 1972),

Microlegia sp. (Ogura, 1972), N. hirta, N. marginata, N. Eilosella, N.

4O
BlatygNzlla, N, sggluncae, N, strigosa, N, trichosticha, N, Wilfordii
(Posthumus, 1936), Notholaena Marantae (Tansley, 1907), Odontosoria
aculeata (Ogura, 1972), Pellaea atropurpurea (Gwynne-Vaughan, 1903;
Ogura, 1972), N, NglggNN_(Gwynne-Vaughan, 1903; Tansley, 1907; Ogura,
1972), N, rotundifolia (Posthumus, 1936), Polypodium punctatum (Gwynne-

 

Vaughan, 1903; Ogura, 1972), Pteris elata, N, incisa, N, ludens, P.

 

scaberula (Gwynne-Vaughan, 1903; Ogura, 1972), Saccoloma (Posthumus,
1924) and Tapeinidium pinnatum (Ogura, 1972).
ECTOPHLOIC SOLENOSTELE: AntrogNzum sp. (Ogura, 1972), Elaphoglossum Sp.

 

(Ogura, 1972), Helminthostachys zgylanica (Ogura, 1972), Ophioglossaceae

 

(Nozu, 1956) and Vittaria (Ogura, 1972).
TRANSITIONAL (Between a solenostele and dictyostele): Adiantum Kaul-

 

‘NN5511.(Gwynne-Vaughan, 1903), N, macrophyllum (Posthumus, 1924, 1936),
N, monochlggzg (Ogura, 1921; Posthumus, 1924, 1936), N, ENNNNNN_(Ogura,
1921), N, geruvianum (Posthumus, 1924, 1936), N, Netiolatum (Posthumus,
1924, 1936), N, tragezforme (Gwynne-Vaughan, 1903; Ogura, 1972),
Alsophila Engelii, Antrophyllum reticulatum (Gwynne-Vaughan, 1903),
Coenopteris scandens (Posthumus, 1936), Cheilanthes Feei (McCulloch
_eNg_1_., 1974), N, gracillima (Posthumus, 1924), N. Kaulfussii, N. 121929.-
N, Ngggyj, N, giggjgg_(McCulloch 23.21:: 1974), Cheilanthes sp. (Gwynne-
Vaughan, 1903; Marsh, 1914), Davallia (Bower, 1928), Diplora longifolia,
N, schizocargg, N, d'Urvillei (Posthumus, 1936), Gymnogramme vestita
(Gwynne-Vaughan, 1903), Lophosoria (Lucansky, 1974), Notholaena sp.
(Ogura, 1972), N, ferruginea (aurea), N, Marantae, NN trichomanoides
(Gwynne-Vaughan, 1903), Ngllggg_sp. (Ogura, 1972), N, andromaedifolia,

 

N, rotundifolia (Gwynne-Vaughan, 1903), Plagiogygia (Bower, 1923),
Pteris arguta, P. biaurita, P. cretica, P. dentata, P. flabellata,

41
N, heterophylla, N, longifolia, N, Nellucida, N, umbrosa, N, Swartziana,
N5 tremula (Bower, 1928), Nuercifilix zeylandica (Posthumus, 1924, 1936)
and Vittaria stigitata (Gwynne-Vaughan, 1903; Posthumus, 1936).
RADIAL SOLENOSTELE: Acrostichum aureum, Ithycaulon (Saccoloma)
domingense, N, inagguale, Lonchitis aurita, N, hirsuta, Pteris arguta, N,
N, orizabae, N, gellucida, N, Nodoghxlla, N, tremula, N, umbrosa and
Saccoloma glgggN§_(Posthumus, 1936).
DICTYOXYLIC SOLENOSTELE: Cheilanthes lendigera (Ogura, 1972), N, EEEEQT
NNzllg_(Gwynne-Vaughan, 1903; Posthumus, 1924, 1936; Ogura, 1972),
NNNNNN_cordifolia (Bower, 1928) and Vittaria stipitata (Ogura, 1972).
PERFORATED SOLENOSTELE: Christiopteris tricuspis (Posthumus, 1936),
Neocheiropteris palmatopedata (Posthumus, 1936), Stromatopteris Sp.
(Bower, 1928).

Thus the solenostelic condition as reported in the literature seems
to exist in great variety and profusion. The problems mentioned con-
cerning protosteles recur again, with an obvious need either for
clarification of and further explanation of stelar conditions in taxa or
a more simplified method of stelar description; I would propose the
latter. -

Gwynne-Vaughan (1903) noticed that there were many transitional
types related to the solenostele, and that the true solenostele was not
of general occurrence. He provided a generalized description of the
habit of the rhizome in which he stated that the ferns with a soleno-
stelic vascular system had a creeping, more or less dorsiventral rhizome
with leaves arranged in two rows on the upper surface. The gaps formed

by leaf trace departures never overlap.

42

Stevensen (1974) noted that Mettenius (1857) observed
parenchymatous gaps that were unrelated to either the leaf or branch
traces in the solenosteles of Saccoloma elegans Kaulf. and
Stenochlaena tenuifolia (Desv.) Moore.

Kuhn (1889) observed the same phenomenon in the solenostele of
Christensenia aesculifolia (Blume) Maxon (as Kaulfussia aesculifolia
Blume), by Brebner (1902), Tansley and Lulham (1904) and Ogura (1938)
in the dictyostele of Danaea simplicifolia Rudge and by Ford (1902) in
the dictyostele of Ceratopteris thalictroides.

Gwynne-Vaughan (1903) also mentioned, and was aware of the fact
that gaps sometimes occur in the vascular cylinder that are not related
in any way to the insertion of leaves. It will be recalled that Schoute
(1938) described a dictyostele as a solenostele with more than one leaf
or other gaps so as to show more than one interruption in any transverse
section.

Tryon (1960) NN_Stevensen (1974) pointed out that Gwynne-Vaughan's
taxa may have been erroneously identified and because he did not file
voucher specimens it is impossible to verify the genera and species he
investigated. Regardless of the proper identification of the taxa,
Gwynne-Vaughan's observations are pertinent (Stevensen, 1974). Gwynne-
Vaughan described the gaps that were unrelated to the appendage trace
as ”lacunae” and considered a solenostele with lacunae as a type of
dictyostele that had evolved without overlapping leaf gaps (Stevensen,
1974). He concluded that this type of stele could be considered a type
of solenostele.

Tansley (1907) applied the term “perforation” to the type of gap
described above and used the designation of ”perforated steles" for
steles having that type of gap (Stevensen, 1974).

43

Stevensen's (1974) work, based on examination of past stelar
reconstructions and diagrams of those who have noted “lacunae“ or “per-
forations,“ has found it impossible to ascertain whether or not the
perforations are related to root traces.

The conclusive, important point made by Stevensen (1974) is that
it may very well be that some dictyostelic forms are not true dictyo-
steles, but appear dictyostelic because stelar root gaps are present
in very close proximity to the leaf traces and their corresponding leaf
gaps.

Brebner (1902) adopted the term dictyostele for the tubular network
of vascular tissue that arises by the occurrence and overlapping of gaps
in a solenostele (Gwynne-Vaughan, 1903).

The term dialystelic was used by Worsdell (1902) to describe the
splitting up of the tubular solenostele into a number of secondary solid
steles or concentric strands. Worsdell stated that the dialystelic
condition was due to the crowded arrangement of the leaves on the stem,
so that frequent gaps in the original solenostele became inevitable.

Gwynne-Vaughan (1903) described two factors that could bring about
the overlap of leaf gaps: first, if each leaf gap remained open long
enough after the departure of the leaf trace; secondly, the same result
would be obtained if the leaves were crowded sufficiently close
together, even if the leaf gaps were to close rapidly.

Tansley (1907) reiterated Gwynne-Vaughan (1903) by stating that
'. . . as soon as two successive leaf gaps have overlapped, either by
crowding of the leaf insertions, or by the prolongation forward of each
leaf gap till it passes the base of the next trace, the stele tech-

nically ceases to be a solenostele by Gwynne-Vaughan's definition and

44
becomes a simple dictyostele, defined as an amphiphloic cylinder in
which at least some transverse sections show two or more leaf gaps.“

Schoute (1938) described a dictyostele as a solenostele with one or
more leaf gaps or other gaps, so as to Show more than one interruption
on any transverse section.

Foster and Gifford (1959) described a dictyostele as an amphiphloic
siphonostele in which parenchymatous leaf gaps overlap.

Esau (1965) described a dictyostele as a type of siphonostele in
which the leaf gaps were large and overlap to the extent that they give
the vascular system a dissected, or net-like appearance.

Fahn (1967, 1974) considered a dictyostele to be a type of amphi-
phloic siphonostele with overlapping gaps.

Ogura's (1972) concept of a dictyostele is one of a cylindrical
stele which is interrupted by numerous leaf gaps so that the Stele
cylinder is separated in a cross section into more than two parts, each
part being a meristele. Ogura (1972) lists ten different types of
dictyosteles: a) transitional between a solenostele and dictyostele,
the solenostele and dictyostele may be found in different levels of an
organism; b) dictyoxylic solenostele, this type is a special case of
the transitional variety and is represented by a solenostelic form whose
xylem ring is interrupted in some parts, that is dictyoxylic; c) typical
dictyostele, the arrangement of leaf gaps is radial, the number and form
of meristeles in a cross section is not constant; d) dorsiventral
dictyostele, having the leaf gaps Situated mainly on the dorsal Side;

e) perforated dictyostele, in addition to leaf gaps, perforated gaps are
fbund, but neither can be distinguished in the cross section; f) Davallia

type, a type of perforated dictyostele, in which two meristeles at the

45

median dorsal and ventral parts are larger than the other meristeles;
g) Oleandra type, a type of perforated dictyostele in which the meri-
steles are arranged alternately; h) ectophloic dictyostele, where the
internal phloem is absent; i) Nglymmg_type, in cross section some
radially elongated concentric meristeles are arranged in a circle, but
the gaps between them are not the leaf gaps; j) Ophioglossaceae type, a
solenostele or dictyostele, but the internal phloem is absent with the
central pith being very large consisting of parenchyma and the internal
endodermis is also absent, but present sometimes in some species.

The following are pertinent dictyostelic conditions and representa-
tive taxa as reported in the literature:
TYPICAL DICTYOSTELE: Acrophorus (Nayar and Kazui, 1962; Nayar and Kaur,
1966), N, Stipellatus (Bower, 1928), Acrostichum m (Bower, 1928),
Actinopteris (Nayar, 1962b), Adiantum assamicum (Nayar, 1964), N,
cagillus W, N, petiolatum, N. trapieziforme (Bower, 1928)
AlsoNhila NNNNNNN.(Gwynne-Vaughan, 1903; Lucansky, 1974), Amplelopteris
Nrolifera (Chandra and Nayar, 1968), Nggmlg_(Boodle, 1901; Posthumus,
1936), NNNNNNN.citrifolium (Bower, 1928), Antroghyum brasilianum. N,
lanceolatum, N, lineatum. N. Nlantagineum, N. reticulatum, N, §_e_n_lj_-
cordatum (Posthumus, 1936), Asglenium cardioghyllum (Posthumus, 1936),
A- m (Posthumus, 1936; Tansley, 1907; Ogura, 1972), A- maminatum
(Bower, 1928), N. dalhousiae, N, m. N. trichomanes, N. exiguum,
N. ensiforme, N. glanicaule, N. laciniatum, N. subinterrifolia, N.
tenuifolium, N. W9 N, cheilosorum, N. unilaterale (Bir, 1957), N.
M (Ogura, 1921), Athzrium (Bower, 1928; Ogura, 1972), N. NM-
53111. N. yokoscence (Ogura, 1921), Belvisia (Tindale, 1961), Blechnum
(Lomaria) tabulare (Bower, 1928; Ogura, 1972), Brainea insignis (Bower,

‘I

Q

46

1928), Coenopteris (Posthumus, 1936), Calymmodon cucullatus (Posthumus,
1936), Ceratopteris thalictroides (Ford, 1902; Stevensen, 1974),
Cheilanthes graci11ima (Bower, 1928), Cibotium sp. (Posthumus, 1936), g,
Menziesii (Ogura, 1930), Cnemidaria sp. (Lucansky, 1974), Coniogramme
fraxinea (Ogura, 1921), m Brunonis (Gwynne-Vaughan, 1903), M-
MM (Ogura, 1941), Cryptflramme g_i_s_p_a_ (Bower, 1928), m-
33r_i§_ (Bower, 1928), m simplicifolia (Brebner, 1902; Stevensen,
1974), Diacalpe (Nayar and Kaur, 1966), _I_)_. a_spidioides (Bower, 1928),
Dicksonia (Ogura, 1972), _Q, Barometz (Gwynne-Vaughan, 1903), W
(Wagner, 1952a), p, M (Bower, 1928), Diplazium §9_r_1_i_1_i.j_, 2. M'
Drzopteris africana, 2. decursiminnata, _D_. gracilescens, N. japonica,
_D_. sophoroides, Q, setigera (Ogura, 1921), Dryopteris sp. (Bower, 1928),
N. cretica, N. Filix-Mas (Posthumus, 1936), Q. cristata (Wardlaw, 1945),
Gramitis (Tindale, 1961), Gymnogranme japonica, g. ygs__ti_i_:_a_ (Gwynne-
Vaughan, 1903), Hemionites (Nayar, 1962b), Nymenolejiis revoluta
(Posthumus, 1936), Lastreopsis (Tindale, 1965), Lithostegia (Nayar and
Kaur, 1966), Loxggranma gy_e_n_i_a_, 1,, gramitoides, 1., involuta, _L_. 139533-
1353, N. malgzaria, _l_._. parallela, N, mexicana, L. perakense, _L_.
Raciborskii (Posthumus, 1936), Matteucia orientalis (Ogura, 1921), 11,
Struthiopteris (Bower, 1928), Microsorium (Nayar, 1963b), m
(Posthunus, 1936), Monachosorum digitatum (Bower, 1928, as [1, Beggiana;
Posthumus, 1924, 1936, as flmolepis Bergiana), Nephelea (Gastony, 1973;
Lucansky, 1974), Nephrolepsis (Bower, 1928; Posthumus, 1936), Niphidium
(Lellinger, 1972), Msensibilis (Ogura, 1921; Bower, 1928),
Ophioglossum lusitanicum (Fahn, 1974), Peranema (Nayar and Kaur, 1963,
1966), N. gyatheoides (Bower, 1928), szllitis scolopendrium (Bower,

 

47

1928), Plagiogygia (Nayar and Kazui, 1962), N, adnata (Ogura, 1921), N,
pyrnophylla (Bower, 1923; Stevensen, 1974), Platycerium (Tindale, 1961),

 

N, alcicorne (Tansley, 1907; Bower, 1923; Stevensen, 1974), Polypodium

 

digitatum, N, Feei, N, hemionitideum, N, lasiostripes, N, Mettenianum, N,

 

 

 

peduncalatum, N, Hrightii (Posthumus, 1936; Stevensen, 1974), Polysti-

 

chum aristatum (Ogura, 1921; Posthumus, 1936), N, aculeatum, N, falcatum,

 

N, lepidocaulon (Ogura, 1921), N, tripteron (Posthumus, 1936), Pteris
podgphylla (Bower, 1928), errosia (Tindale, 1961), Sadleria (Posthumus,

 

1936), Scyphularia pentaphylla (Posthumus, 1936), Nphaeropteris

 

(Lucansky, 1974), Stenochlaena sorbifolia (Bower, 1928), Stenosemia

 

 

aurita (Posthumus, 1936), Trichipteris (Lucansky, 1974), Vittaria sti i-
tata (Posthumus, 1936), Woodsia (Bower, 1928; Brown, 1964; Ogura, 1938)
and Hoodwardia radicans v. orientalis (Ogura, 1921).

 

 

 

RADIAL DICTYOSTELE: Acrophorus stipellatus (Posthumus, 1936), Adiantum

 

aethiopicum, N, gracillima (Posthumus, 1936), N, lunulatum (Gwynne-

 

Vaughan, 1903; Posthumus, 1924), N, nuiguineense, N, philippense

 

(Posthumus, 1936), Anggramma subdigitatum (Posthumus, 1936), Anopteris

 

hexagona (Posthumus, 1936), Asplenium (Posthumus, 1924), N, germanicum,
A. ruta-muraria, N, septentrionale (Posthumus, 1936), Athyrium alpestre,

 

N. filix-femina, N. nipponicum, N. yokoscense (Posthumus, 1936),

 

 

Blechnum attenuatum, N, brasiliense, N, capense, N, discolor, N,

 

filifbrme, N, integripinnulum, N, gipponicum, N, Patersoni, N,

 

pennamarina, N, punctulatum, N, spicant, N, tabulare (Posthumus, 1936),

 

Brainea insignis (Posthumus, 1936), Camptosorus sibericus (Posthumus,
1936), Ceratopteris thalictroides (Bower, 1928), Ceterach officinarum
(Posthumus, 1936), Cheilanthes persica (Posthumus, 1924, 1936; Bower,

 

1928), Coniogramma fraxinea, N, japonica (Posthumus, 1936), Cryptogramma

48
511.22; (M SLEEP—5.. Posthumus, 1924), Cyrptomium W
(Posthumus, 1936), Czstogteris fragilis, N. jagonica (Posthumus, 1936),
Diacalge (Posthumus, 1936), Dicksonia Barometz (Gwynne-Vaughan, 1903),
Niggnochlaena truncatula (Posthumus, 1936), Nj3_1_l_i_a_g_r_‘¢_3_c_t_a_, N. falcata
(Posthumus, 1936), Diaplazigpsis japonica (Posthumus, 1936), Diapjazium
esculentumJ N. japonicum, N. ma_rginatum, N. proliferum, N. Pullingeri,
N. striatum, N. ultidifolium, N. Hichurae (Posthumus, 1936), 22.9211
mm (Posthumus, 1936), Dryopteris africana, N. cristata, N.
deconvosita, N. decursive-pinnata, N. filix-mas, N. gongylodes, N.
gracilescens, N. hirtiges, N. jagonica, N. Linneana, N. Miqueliana, N.
oreopteris, N. pheg0pteris, N. Robertiana, N. 52inulosa, N. (L011-
stichum) Standishii, N. thelypteris, N. tokyoensis, N. trighzlla, N.
3231!. (Posthumus, 1936), Gflnnogramne Calomelanos (Gwynne-Vaughan, 1903),
Hemigrama latifolia (Posthumus, 1936), Hemionites 9.9.3992 (Gwynne-
Vaughan, 1903; Posthumus, 1936), Ngu_a_r_i_a_ semicordata (Plagiogyria
biserrata, Gwynne-Vaughan, 1903), Lomariopsis sorbifolia (Posthumus,
1936), Matteuccia intermedia, N. japgnica, N. orientalis, N. struthiog-
N131; (Posthunus, 1936), Monachosorella flagellaris, N. Maximowiczii
(Posthumus, 1936), Nephrolepis acutifolia, N. biserrata, N. cordifolia
(Posthumus, 1936), Oleandra articulata, N. neriifonnis (Posthumus, 1936),
NW sensibilis (Posthumus, 1936), Peranema gatheoides (Posthumus,
1936), Phyllitis scolopendrium (Posthumus, 1936), Pitzrogramna
Calomelanos, N. peruviana, N. tartarea, N. triangularis (Posthumus,
1936), Plagiogaia m, N. Ezenoghylla, N. semicordata (Posthumus,
1924), Polxbotrza cervina, N. osmundacea, N. serratifolia (Posthumus,
1936), Polzstichum aculeatum, N. auriculatum, N. craspedosorum, N.
legidocaulon, N. M, N. lonchitis (Posthumus, 1936), Prosagtia

49
(Posthumus, 1924), N. alata, N. contigua (Posthumus, 1936), Pteris

 

W, N. flabella, N. heterophylla, N. Bellacida, N. tremula (Gwynne-
Vaughan, 1903), Sadleria cyatheoides (Posthumus, 1936), Taenitis
blechnoides (Gwynne-Vaughan, 1903; Posthumus, 1936), Tectaria chatta-
gramica, l. irregularis, 1. M31, 1. macrodonta, I, tenerifrons
(Posthumus, 1936), Woodsia ilvensis, N. 9_b_i;u_s_a_i_ (Posthumus, 1924), N.
polystichioides (Posthumus, 1936) and Woodwardia radicans (Posthumus,
1936).

DORSIVENTRAL DICTYOSTELE: Adiantum macrophyllum, N. trageziforme
(Posthumus, 1924; Ogura, 1972), Aglaomorpha drynarioides, N. heraclea
(Posthumus, 1936), Ananthacorus angustifolia (Posthumus, 1936), Anetium
citrifolium (Posthumus, 1936), Anthrophyum (Bower, 1928), Araiostegia

Nmnoggzlloides, N. p_u1chra (Posthumus, 1936), Arthropteris
altescandens, N. obliterata, N. orientalis, N. tenella (Posthumus, 1936),

 

Asglenium 1153191 (Ogura, 1972), Bolbitis 11.1211: N. hetero-clita, N.
nicotianifolia, _B, m (Posthumus, 1936; Ogura, 1972), Cheilanthes
Ne_e_i_ (Posthumus, 1924, 1936), N. Fendleri, N. gracillima, N. lendigera,
(Posthumus, 1936), NNclophorus lanceolatus (Posthumus, 1936), Davallia
m (Posthumus, 1924), N. canariensis, N. divaricata, N. [13:13:31,
N. gxxidata, N. £11191, N. trichomanoides (Posthumus, 1936), NM-
Mzgzlanica (Ogura, 1972), Egenolfia (Nayar and Kaur, 1964b;
Ogura, 1972), Elaghoglossum (Posthumus, 1924), N, breviges, N, szridum,
N. latifolium, _E_. 3.1.9.933: N. M, N. m, _E, tomentosa
(Posthumus, 1936), Asplenium obtusifolium, N, unilaterale (Posthumus,
1936), gmogteris Elf!» N. m (Posthumus, 1936), mm-

mm, N. garvula, N. regens, N. vestita (Posthumus, 1936),
Nypodematium (Ogura, 1972), Nzgoderis Brownii (Posthumus, 1924, 1936),

H“

50
Leptochilus axillaris, N, decurrans (Posthumus, 1936), N, heteroclitus,
N, nicotianifolius (Ogura, 1972), Lithostggia foeniculacea (Posthumus,
1936), Lomagramma guianensis (Posthumus, 1936), Merinthosorus
drynarioides (Posthumus, 1936), Microggamma vacciniifolia, Notholaena
ferruginea (22322): N, Marantae (Posthumus, 1924, 1936), N, NNNNNNN, NN
triangularis (Posthumus, 1936), N, trichomanoides (Posthumus, 1924,
1936), Ngllggg.andromaedifolia, N, atropurpurea (Posthumus, 1924, 1936),
N, NggNgNg_(Gwynne-Vaughan, 1903; Posthumus, 1924), N, rotundifolia
(Tansley, 1907; Posthumus, 1936), Platycerium bifurcatum, N, stemaria
(Posthumus, 1936), Polypodium accedens, N, angustifolium, N, aureum N,
M, N. fuscipunctatum, N. m, N. loriceum, N. Lycopodiodes, N.
Egrcussum, N, pgrsicariaefolium, N, garadisae, N, piloselloides, N,
Eterogus, N, gunctatum, N, sub-hastatum, N, subrostratum, N, squamulosum,
N; sinuosum (Posthumus, 1936), Polystichum adiantiforme (Posthumus,
1936), Rhipidopgeris Ngllggg.(Posthumus, 1936) and Vittaria lineata
(Posthumus, 1936).
PERFORATED DICTYOSTELE: Adiantum (Ogura, 1972), Asplenium ensiforme
(Ogura, 1972), Christopteris tricuspis (Bower, 1928), Ng22512_(Athzrium)
grolifera, N. concinna, N. M (Bower, 1928), Diacalgg (Ogura, 1972),
Dgzgaria heterophyllum, N, quercifolia (Posthumus, 1936), Neocheirop-
jggj§_ga1mato-gedata (Bower, 1928), Oleandra (Ogura, 1938), Polypodium
lasiostiges (Ogura, 1972), Pteridium aquilinum (Posthumus, 1936) and
Stenochlaena tenuifolia (Posthumus, 1936).
DAVALLIA DICTYOSTELE: Davallia (Ogura, 1972) and NNNNNN_(Ogura, 1972).

OLEANDRA DICTYOSTELE: Oleandra (Ogura, 1972).

51
ECTOPHLOIC DICTYOSTELE: Anthrophyum (Ogura, 1972), Pteridanetium (Ogura,

 

 

1972) and Vittaria (Ogura, 1972).
KALYMMA TYPE DICTYOSTELE: Kalxmma (Ogura, 1972).
OPHIOGLOSSACEAE DICTYOSTELE: Botrychium (Ogura, 1972), Cheiroglossa

 

 

(Ogura, 1972), Ophioderma (Nphioglossum) pendulum (Ogura, 1972), Oghios-

 

saceae (Ogura, 1972) and Rhizoglossum (Ogura, 1972).

 

The dictyostelic type is highly variable as witnessed by the exten-
sive types of conditions noted from the literature. Problems of overlap
of genera and species are once again encountered; a few of which will be

noted. Diella falcata has been recorded as a radial dictyostele, a

 

typical dictyostele, and a typical solenostele; N99N§jg_is described as
being a typical dictyostele but N. ilvensis, N. 913N131 and N. M-
stichioides are described as radial dictyosteles; Adiantum has been
described as a typical solenostele, transitional from solenostele to

dictyostele, and a perforated dictyostele.

I. ONTOGENY - THE STELE
Tansley (1908) made the following reference as to the developmental
stelar sequence:

We always find a protostelic structure in the first
formed stem, and in the protostelic types, so far as evidence
is available, this structure is retained throughout the stem,
the stele merely increasing in size in relation to the larger
and larger leaf traces that have to be supplied . . . 0f
the ontogenetic history of the Lindsaya-type of stele we
know, unfortunately, nothing; but when we pass to the
solenostele type we find that the first formed stele is
again a protostele, giving off simple leaf traces, that
it then passes through a Lindsaya-phase, in which an internal
phloem, continuous with the inner phloem of the leaf trace,
appears in the center of the stele.

The ontogenetic development of dictyostely through solenostely is

52
illustrated for Notholaena (Nothochlaea) sinuata and it clearly
demonstrates protostely, solenostely and dictyostely. The developmental
sequence of dictyostely in Polypodium NNNNNN_is illustrated and the
original protostelic condition is obvious.

Thompson (1920) stated that: “By common consent protostely has
been recognized as a primitive state . . . it figures universally in the
juvenile plants of the Filicales, and is maintained in the adult stems
of a number of their primitive genera." Specifically Thompson cited a
number of examples: Schizaea malaccana has a protostele in the young
portion of the stem. The ontogeny of Gleichenia pectinata is well known
and it illustrates a progression from a protostele in the sporeling to a

solenostele in the adult. Lindsaza adiantifolia illustrates a solid

 

protostele stage (page 726) as does Loxsoma Cunninghammi, although the
solenostelic condition is delayed in this species until many leaves have
been fbrmed. In Acrostichum Nggggg_the protostelic stage is very brief,
but nevertheless, well illustrated (Figure 9, page 730). He continues,
”The ontogenetic condensation thus shown fbr Acrostichum Nggggm_appears

also in Cheilanthes, and in Pteridium aquilinum, and Paesia podgphylla

 

and may be expected to figure generally for plants of Pterid affinity."
Ogura (1963) made the following statement:

It is well known that in species in Filicales, which
show the solenostelic or dictyostelic system in the adult
stems, the sporelings show a protostelic system. Such a
protostelic system is small, consisting of a few elements,
and if we trace the ontogeny of the stele, we will see the
formation of parenchyma group, or the pith, within the
xylem, so that the protostelic stage is seen in a very
short distance.

Ogura (1972) made the following remarks regarding the ontogeny of
the stelar system: "As described befbre, the youngest, that is, the

53
first fbrmed part of the stem is small and its stele shows a very simple
protostele, or the primitive protostelic type, consisting of a few
tracheids and sieve tubes."

Esau (1965) contributed the following: "The simplest type of stele,
and also the most primitive phylogenetically, contains a solid column of
vascular tissue enclosing no pith. This is the protostele . . .
Protosteles are most common in the lower vascular plants, but they occur
also in the stems of some angiospermous water plants.“

Fahn (1974) made the following statement: "Research on
Oghioglossum 1usitanicum (Gewirtz and Fahn, 1960) for instance showed
that the stele of the rhizome of the sporophyte of this species that
developed from the gametophyte (not as a result of vegetative reproduc-
tion) was protostelic at the base and siphonostelic (dictyostelic) in
its upper portion.“

Foster and Gifford (1974) state that many investigators have shown
that the older portion of a fern stem is protostelic, but at a higher
level (that is, younger portion) of the same stem the vascular cylinder
may be solenostelic or dictyostelic.

Recently Webb (1975) makes these observations concerning the
ontogeny of the stele in Oghioglossum petiolatum: "At the base of the
stem is a protostele surrounded either partially or completely by phloem.
Above this point pith develops, and the stele is an ectophloic siphono-
stele. The remainder of the stem contains a dictyostele of anastomosing
collateral bundles with endarch xylem and no secondary vascular tissues.”

Most recently Lucansky and White (1976) demonstrated the onto-
genetic development of §phaeropteris elongata and Lophosoria guadripin-
2252, It was shown that N, elongata progressed from, at the oldest

54
portion, a protostele, apically to a solenostele and than a dictyostele.
Lophosoria quadripinnata progressed from a protostele, in its oldest
portion, to a solenostele; the dictyostelic condition was not seen in

this taxon.

J. ECOLOGY - THE STEM

In the Introduction the general habit and ecologic relationships of
the Cheilanthoid ferns were described. In the Observation section more
specific information regarding each taxon's growth habit and ecological
niches will indicate a fairly high degree of specialization and adapta-
tion.

To endure such a rigorous environment (xerophytic conditions) a
perennial plant has to be able to withstand the dessication that results
from high temperatures, high light intensities, low water supply and
harsh edaphic conditions (Hevly, 1963).

Maximov (1929, 1931), Eames and MacDaniels (1947), Shields (1950)
and Daubenmire (1959) noted many structural modifications important in
controlling water loss in xerophytes, Hevly (1959, 1963) found these
adaptations to exist in the Cheilanthoid ferns. Of particular interest
to us is his description of the modifications of the rhizome. "Water
loss in Cheilanthoid ferns may further be controlled by impregnation of
the cell walls of the epidermis and cortex with suberin and lignin, par-
ticularly in the rhizome and stipe. The sclerification of the cell
walls may extend to the stele in such ferns as N, 5122222.a"d its close
allies.” These specialized cell layers probably play the same role in
these ferns as in sclerophyllous plants where they are believed to

prevent water loss through their impermeability to water (Eames and

55
MacDaniels, 1947). The effect of wall impregnations is heightened by
the filling of the cells in the cortex by gum or tannin-like substances.
It is also augmented by the sclerification of the epidermal appendages
of the rhizomes and stipes in such species as N, californica Eaton, N,
Standlezi Maxon, N, Galeottii Fee and N, Nggxi Davenp. (Hevly, 1963).
These features were noted in all Specimens examined.

The presence or absence of some of these factors is thought by many
to be controlled by environmental factors such as water deficit, high
light intensity, nitrogen deficiency and temperature (Shields, 1950,
1951).

Hevly (1963) has demonstrated that when the Cheilanthoid ferns are
grown in greenhouses or transplanted to cooler regions, “. . . they
retain their typical growth habit and associated anatomical and mor-
phological alterations.“ He further stated that these characters were
genetically fixed, and, if effective in controlling water loss, the
characters should be considered true adaptations to xeric conditions.

Hardlaw's (1945) data and analysis indicated that the mode of dis-
tribution of metabolites and the development of mechanical stresses in
the formative region may be factors in the morphological development of
the stele, i.e. non-hereditary factors may play an important part in
determining shoot organization.

MATERIALS AND METHODS

The following Species of Notholaena were utilized in this study:

 

N, Aschenborniana Klotzsch, Garcia Caves, 36 mi. w. of Monterrey, Nuevo
Leon, Mexico, Aug. 19, 1971, McCulloch 32-71; N, 22322.(P°ir) Desv.,
road from Monterrey to Saltillo, Coahuila, Mexico, Aug. 26, 1971, I. W.
Knobloch 2483; N, brachygus (Kze.) J. Sm., Ahuacatlan Nayarit, July 18,
1960, I. W. Knobloch 1645; N, candida (Mart. and Gal.) Hook. var.
candida, Tacuina, Chihuahua, Mexico, Aug. 12, 1967, I. W. Knobloch 2288;
N, candida var. Copelandii (C. C. Hall) Tryon, Rio Elizondo, 5 mi. so.
of Monterrey, Hwy. 85, Nuevo Leon, Mexico, Aug. 17, 1971, McCulloch
14-71; NN cochisensis Goodding, McKelligan Canyon, El Paso County,
Texas, Sept. 9. 1971, I. w. Knobloch 2493; N. Galeottii Fee, 15 mi. so.
of Huajaupan de Leone, Oaxaca, Mexico, Aug. 15, 1966, I. N. Knobloch
2198; N, Nggyl.0avenp., El Aguaje, 38 1/2 mi. w. of Chihuahua,
Chihuahua, Mexico, Aug. 5, 1964, I. N. Knobloch 2078; N, interegerrima

 

Hook., Garcia Caves, 36 mi. w. of Monterrey, Nuevo Leon, Mexico, Aug. 19,
1971, McCulloch 31-71; N, Lemmonei D. C. Eaton, Mexico, §,N,; N,
limitanea Maxon var. mexicana (Maxon) Broun, Puenta e1 Chorro 3, Rt. 57
so. of Saltillo, Coahuila, Mexico, Aug. 21, 1971, McCulloch 59-71; N,
ngglecta Maxon, Huasteca Canon, so. of Santa Catarina, Nuevo Leon,
Mexico, Aug. 24, 1971, McCulloch 85-71; N, Newberrzi D. C. Eaton, garden
of Dr. Hoover, San Diego County, California, I. W. Knobloch aq. no.

71-16; N, parvifolia Tryon, El Paso, Texas, Aug. 1, 1960, I. W. Knobloch
56

57

1687; N. 5.13.191 Davenp., Victoria-Jaumave Rd., Tamaulipas, Mexico,
Sept. 9, 1966, I. N. Knobloch 2244; N, Schaffneri (Fourn.) Underw. ex
Davenp. var. Schaffneri, Barranca Oblatos, Guadalajara, Jalisco, Mexico,
Aug. 9, 1970, I. N. Knobloch 2478; N, sinuata (Lag. ex Sw.) Kaulf.,
rd. to Chipinque Mesa, Nuevo Leon, Mexico, Aug. 20, 1971, McCulloch
43-71; N, Standleyi Maxon, Puenta e1 Chorro 3, Rt. 57 so. of Saltillo,
Coahuila, Mexico, Aug. 21, 1971, McCulloch 60-71.

The following species of Pellaea were used in this study:
N, allosuroides (Mett.) Hieron., Majalca, Chihuahua, Mexico, Aug. 4,
1964, I. w. Knobloch 2069; N. andromaedifolia (Kaulf.) Fe/e, Siskiyou

Nursery, Medford, Oregon, I. H. Knobloch aq. no. 71-22; EB atropurpurea

 

(L.) Link, Gardens of the Blue Ridge, North Carolina, 1971, I. N.
Knobloch aq. no. 71-30, and Cahon de San Francisco above Villa Santiago,
Nuevo Leon, Mexico, Aug. 23, 1971, McCulloch 78-71; N, brachygtera
(Moore) Baker, Siskiyou Nursery, Medford, Oregon, 1965, I. N. Knobloch
aq. no. 65-13; N, NNNN951_D. C. Eaton, Sierra Nevada Mountains, Fresno
County, Sept. 1971, Taylor §:flbv I. W. Knobloch aq. no. 71-29; N,
Bridgesii Hook., Stanislaus National Forest at Pinecrest, California,
Sept. 12, 1971, Rodin §,N,, I. W. Knobloch aq. no. 71-26; N, dealbata
(Pursh) Prantl, Colorado River below Miller Dam, Austin, Travis County,
Texas, Jan. 8, 1969, Seigler 1034, I. N. Knobloch aq. no. 72-4; N,
falcata (R. Br.) Fée, Antonelli Brothers, California, May, 1972, I. W.
Knobloch aq. no. 72-7; N, intermedia Mett. ex Kuhn, Puenta e1 Chorro 3,
Rt. 57 so. of Saltillo, Coahuila, Mexico, Aug. 21, 1971, McCulloch
57-71; N, lgNgimucronata Hook., so. on a road to Madera Canyon, Arizona,
July, 1971, Pinkava and Brown 615, McCulloch aq. no. 71-5; N, mucronata

(D. C. Eat.) D. C. Eaton var. californica (Lemmon) Munz and Johnston,

58
near Redding, California at Slate Creek, June 14, 1971, Rodin, §,N,,
McCulloch aq. no. 71-18, and Siskiyou Nursery, Medford, Oregon, 1971,
McCulloch aq. no. 21-21; N, notabilis Maxon, Cafion de San Francisco,
above Villa Santiago, Nuevo Le6n, Mexico, Aug, 23, 1971, McCulloch
79-71; N, eteroides (L.) Prantl, Univ. of Capetown, South Africa,
Schelpe §,N,, I. N. Knobloch aq. no. 73-6; N, Skinneri Hook., near
Temoris station on Chihuahua a1 Pacifico R.R., Chihuahua, Mexico, Aug. 7,
1964, I. W. Knobloch 2089; N, viridis (Forsk.) Prantl var. viridis (as
identified by Dr. E. Schelpe), Greenhill Nursery, loc. unknown, McCulloch

aq. no. 71-33; N, X Wrightiana Hook., Malino Basin, Catalina Mountains,

 

Arizona, July 8, 1960, I. W. Knobloch 1624.

Rhizomes were taken from collected plants by the author in 1971,
from greenhouse grown plants of the author and Dr. I. N. Knobloch at
Michigan State University, from plants purchased from various nurseries
(identified, checked and corrected by the author and Dr. I. W. Knobloch)
or from plants which had been given to the author or Dr. I. W. Knobloch
by various individuals, as noted in the paragraphs above. Fronds were
collected for the purpose of making voucher specimens and such sepcimens
were deposited in the Michigan State University Herbarium (MSC).

Roots were removed as were most of the scales on the rhizomes. The
rhizomes were killed and fixed in Formalin-acetic-alcohol (FAA).

Dehydration of the rhizomes was accomplished by using a tertiary-
butyl-alcohol series (Table 2), modified from Sass (1958).

The dehydrated rhizomes were then placed in an aSpirator to ensure
that all the air was removed from the specimen for proper infiltration
with paraffin. A minimum of two hours was used as a standard for evacua-

tion, with as long as twenty-four not being unusual for some specimens.

TABLE 2.

59

Dehydration series as modified from Sass (1958).

 

Solution number

Solution composition

Time in solution (hr.)

 

 

50
4O
10

30
50
20

15
50
35

25
75

CC.
CC.
CC.

CC.
CC.
CC.

CC.
CC.
CC.

CC.
CC.
CC.

CC.
CC.

distilled water
95% etoh
tertiary-butyl—
alcohol

distilled water
95% etoh
tertiary-butyl-
alcohol

distilled water
95% etoh
tertiary-butyl-
alcohol

distilled water
95% etoh
tertiary-butyl-
alcohol

100% etch
tertiary-butyl-
alcohol

100% tertiary-butyl-
alcohol ;

24

24

24

24

24

2-3, with
3 changes

 

60
Following this procedure the Specimens were infiltrated with
Fisher's Tissue-mat paraffin at 60 degrees C. Table 3 outlines the
infiltration process as was employed for each taxa, as modified from

Sass (1958).

TABLE 3. Paraffin infiltration as modified from Sass (1958).

 

 

 

Infiltration medium Time (hr.) Temp. (C.)
25% paraffin 24 60
75% tertiary-butyl-

alcohol
50% paraffin 24 60
50% tertiary-butyl-

alcohol
75% paraffin 24 60
25% tertiary-butyl-

alcohol
100% paraffin 2, 60

3 changes

100% paraffin 24 60

 

The rhizomes were then cast in paraffin. To accomplish this the
following had to be assembled and ready for use: paper "boats,” a slide
warmer adjusted to 35 degrees C., an ice bath, a Bunsen burner, a needle
probe and a Supply of hot 100% paraffin. Paper boats are shown in
Figure 1. The sides of the boats must be high enough to hold as much
paraffin as will cover the Specimens. Labels with the collection num-
ber or other identifying number are placed in the liquid paraffin. The
paper boats are placed on the hot end of the slide warmer. The paraffin
is allowed to harden a little on the bottom of the boat by gradually

61

Figure 1. Paper boat to hold paraffin and
rhizomes.

62
moving the boat to the cooler end of the slide warmer, but the top is
kept liquid by applying heat from the Bunsen burner. When the paraffin
on the bottom has firmed up, about one-eighth of an inch, the rhizomes
were poured into the boat. The rhizomes were arranged with their cross
sectional surface parallel to the Side of the boat. The specimens were

arranged with a hot needle probe until their orientation was correct.

 

 

 

 

 

 

 

 

The paraffin was gradually cooled from the bottom up to ensure
evenness throughout the block. As the top of the block began to cool,
the boat was pushed under water in the ice water bath and the paraffin
firmed up. After thirty seconds to a minute, the boat was removed from
the ice water bath and the paper removed. The blocks were then placed
in a refrigerator overnight to firm up the paraffin evenly and help
prevent crystal formation. The block was then ready to trim into
smaller blocks for sectioning. Blocks for sectioning were trimmed

using a single-edged razor blade. After the blocks were cut and

63
trimmed, the cross sectional surface of those blocks to be sectioned
was exposed. The blocks were placed in a jar with enough water in them
to cover the specimen and placed in an incubator at about 40 degrees C.
This was done to soften the tissues for sectioning in hopes that it
would prevent tearing in highly sclerified specimens.

Paraffin blocks were mounted on specimen holders and thin paraffin
sections were cut on an American Optical rotary microtome, model number
820. Tables 4 and 5 indicate the thickness at which the best sections
for each taxa were obtained.

The thin sections were then adfixed to chemically clean microscope
slides using either Weaver's solution or Mayer's egg albumin. The
slides were placed on a slide warmer for approximately twenty-four
hours. The slides with thin sections adfixed were then ready for stain-
ing.

A flow diagram for the decerating, staining, clearing and mounting
of thin sections is outlined in Figure 2.

The prepared slides were left to dry for a minimum of twenty-four
hours with weights placed on top of the coverslips to press out excess
mounting media and air bubbles. The slides were then cleaned with
xylene.

Tables 4 and 5 list the staining times best suited for the speci-
mens used at the thickness indicated, other times were tried on many
occasions, and the times listed are a matter of trial and error for the
most part.

Photographs of the specimens were taken utilizing the following
equipment: Nikon 70225 binocular microscope with a Microflex Model EFM,

semi-automatic photomicrographic attachment with a reflex viewfinder

64

Figure 2. Flow diagram for decerating,
staining, clearing and mounting.

65

100% xylene (5 minutes)----100% xylene (3 minutes)----
8100! xylene:glOO% etoh (2 minutes)----lOO% etoh (1 minute)
95% etoh (l minute)----70% etoh (l minute)----50% etoh

(l minute)----30% etoh (l minute)----15% etoh (1 minute)----
1% aqueous safranin (fbr times see Table 4 and 5)----
distilled water (wash)----distilled water (wash)----observe
under microscope (restain if necessary)----15% etoh (time
variable)----30% etoh (time variable)----50% etoh (time
variable)----70% etoh (time variable)----O.5% fast green

in 95% etoh (for times see Table 4 and 5)----95% etoh
(wash)----95% etoh (wash)----lOO% etoh (time variable)----
klOO% xylene:§lOO% etoh (time variable)----Carbol-xylene
clearing solution (30 sec.)----lOO% xylene (30 sec.)----
100% xylene (3O sec.)----add mounting media (Balsam or
Clarite) and coverslip.

66

 

 

 

 

 

 

 

 

 

 

TABLE 4. Section thickness and staining times of Notholaena.
Section Staining times (Sedi)
Species thickness (u) safranin fast green
N, Aschenborniana 10-12 60 45
N, aurea 14 75 50
90 60
60 45
N, brachxgus 20 90 60
N, candida v. candida 18 120 45
N, candida v. Copelandii 9 60 45
N, cochisensis 10 60 45
12 75 50
N, Galeottii 12 60 45
N, Grgzi 18 60 45
N, integerrima 12 65 45
N, Lemmonii 14 6O 45
EN limitanea v. mexicana 12 60 45
N, neglecta 10 6O 45
N, Newberrzi 10 60 60
16 65 60
NN parvifolia 12 60 45
N. rigida 14 6O 45
" 75 60
18 100 60
N, Schaffneri 18 6O 45
N, sinuata 10 60 60
N, Standleyi ll 65 60
12 75 50
16 80 55

 

67

TABLE 5. Section thickness and staining times of Pellaea.

 

 

 

 

 

 

 

 

 

 

 

 

 

SPEC‘ES th1§:§:;2n(4) 53:3:2329 ti?§:t(sec')
green

N, allosuroides 12 60 45
_, andromaedifolia 18 60 45
20 8O 60

N, atrgpurpurea 10 60 50
N, brachyptera 16 60 45
N. m 10 6O 45
N, Bridgesii 10 60 45
N, dealbata 12 6O 45
N. m 18 60 45
N, intermedia 9 55 45
N, longimucronata 10 6O 60
N, mucronata v. californica 16 75 60
18 75 60

N, notabilis 10 6O 55
NN ovata 12 60 45
N. eteroides 18 75 50
N5 Skinneri 14 100 60
‘N, viridis v. viridis 10 75 50
90 60

N, X Wrightiana 16 75 55

 

 

MIN

NV”

68
and coupled CdS exposure meter. The camera body was a Nikon M-SSS dark
box. Kodak Tri-X black and white film (ASA 400) was utilized for all
photographs.

Due to the large diameter of most of the rhizome cross sections,
it was impossible to include the complete section in one picture.
Therefore, photographs of portions of the rhizome were put together for
composite pictures. Photographs were taken at 40X with a shutter Speed
of 1/125 or l/250th of a second. The composite pictures were trimmed
to the outline of the rhizome cross section, placed on a gray mat-board
background, covered with glare-proof glass and photographed.

In order to obtain more specific information about the nature of
the xylem cells, Jeffrey's (1902) method for maceration was employed.
Jeffrey's fluid consists of equal volumes of 10% chromic acid and 10%
nitric acid. The tissues were treated for two days at 37 degrees C.
Following treatment, the xylem tissue was washed and shaken with glass
beads and the fluid decanted off. The tissue was then treated with 10%
Chlorox which aided in bleaching the tissues. Chlorox treatment lasted
about one-half hour. The Chlorox was decanted off and 1% aquous
safranin was added for a stain. The tissue was then placed on a micro-
scope slide and viewed under 400x total magnification. Polaroid
pictures were taken utilizing type 107 black and white Polaroid film on
the Nikon photomicroscope as described before.

In an attempt to document the ontogeny of the stele in at least
one species, thin sections of the rhizome from living Pellaea viridis
were made. Living specimens of N, viridis were obtained from the green-
house of Normandale Community College. The adventitious roots and

fronds were removed from the rhizome by using a single-edged razor

N

‘I

69
blade. The most basal (the oldest area) portion of the rhizome was
then examined. The old gametophyte was found to be still attached to
the sporophyte. The last one-quarter of an inch of the rhizome,
including the gametophyte, was cut off with a sharp, single-edged razor
blade. The rhizome was mounted and then sectioned at 10 to 12 microns
on an IEC model CTD Harris microtome cryostat. Wet mount slides were
made of the sections, observed and photographed with the photomicro-
graphy equipment mentioned before. The Polaroid camera and type 107
black and white Polaroid film was used. Shutter speeds of 1/25 and
1/250th of a second were utilized.

OBSERVATIONS

The following observations will treat the Species of each genera
alphabetically and will include pertinent ecological and rhizome habit
information. Photographs accompany the descriptions and illustrate the
species in a mature anatomical condition which, in each case, was
typical for the sections examined. Anatomical differences and similari-
ties will be pointed out briefly, but in much more detail in the

Discussion section.

Figure 3 illustrates a generalized rhizome cross section. The
tissue layers and other features of the rhizome will be referred to by
the letter key which is described with Figure 3. The plates through-
out the text will include other rhizome features as they occur in some
sections; these will be indicated and keyed in the text.

Notholaena Aschenborniana Klotzsh, McCulloch 33-71.

The rhizome habit of this species is stout, shortly-creeping,
densely clothed with scales, ascending, branched and multicipital.

The habitat has been described as rocky slopes and ledges and in
deep limestone canyons up to 1,600 m. and as dry rocks and cliffs pre-
ferring or perhaps confined to limestone, up to 1500-3000m.

The epidermis is one-celled thick and intact fbr the majority of

the rhizome diameter.

70

71

Figure 3. Generalized rhizome cross section.
Key to symbols: e, epidermis; c, cortex; oen,
outer endodermis; opc, outer pericycle; oph,
outer sieve cells and phloem parenchyma; x,
tracheids and xylem parenchyma when present;
iph, inner sieve cells and phloem parenchyma;
ipc, inner pericycle; ien, inner endodermis;
pi, pith; lg, leaf gap; 1t, leaf trace; art,
avantitious root initiation; Sc, rhizome

sca es.

72

 

 

 

 

 

73

Figure 4. N, Aschenborniana. Cortex. Outer
half to left. X100. Figure 5. N. Aschenbor-
niana. Portion of vascular cylinaer. Ffiloem,
pericycle and xylem. X100.

74

 

75

The outer one half of the cortex is unsclerified (left area) and
the inner portion heavily sclerified (right area) in Figure 4.

Both outer and inner endodermal areas are partially torn. The
outer endodermis constitutes the innermost layer of the cortex.

The outer (opc) and inner (ipc) pericycle regions have two to three
cell layers of thin walled parenchyma cells (Figure 5).

The outer (oph) and inner (iph) primary phloem are composed of
narrow bands of sieve and parenchyma cells (Figure 5). The phloem paren-
chyma cells are smaller than those of the pericycle and can be seen in
Figure 5. The Sieve cells can be distinguished from the phloem paren-
chyma by their apparent lack of nuclei.

The primary xylem consists of scalariform tracheids (x) (Figure 5)
and no xylem parenchyma is present. In cross section it is impossible
to distinguish proto and metaxylem and the common practice of referring
to the smaller of the cells as the protoxylem and the larger of the
cells as the metaxylem will be adhered to in this paper; this will be
discussed more fully under Discussion.

Notholaena Aschenborniana is considered to possess a solenostelic
vascular system.

Notholaena Ngggg.(Poir.) Desv., Knobloch 2483.

The rhizome habit is thick, shortly-creeping, ascending and densely
scaly.

The habitat is talus slopes and in crevices of ledges and cliffs,
on canyon walls and the base of boulders up to 2100 m.

Figure 6 illustrates a complete rhizome cross section of Notholaena
Ngggg_in which a solenostele is present. Two adventitious roots (art)

can be seen arising from the outer pericycle. Two stipe cross-sections

76

Figure 6. N. aurea. Complete rhizome cross
section, soTenostele. x40. Figure 7. N,
aurea. Portion of the vascular cylinder plus
ad3acent tissues. X100.

77

 

78

Figure 8. N, aurea. Longitudinal section of
primary xylem sfiowing scalariform tracheids.
X400.

79

 

80
(st), each with two vascular bundles, can also be noted (Figure 6). In
all of the sections examined (14) the solenostelic condition was seen.

The one-celled thick epidermis was intact. Immediately beneath the
epidermis is a lightly sclerified area of cortex (c) followed interiorly
by a heavier sclerified area and then an area of cortex very lightly
sclerified (Figure 6).

Both outer (oen) and inner (ien) endodermal layers are adjacent to
outer (opc) and inner (ipc) pericycle (Figure 7) which is three to four
cells thick and characteristically stains for starch.

The sieve cells of both outer (oph) and inner primary phloem (iph)
are few and scattered and interrupted by phloem parenchyma cells
(Figure 7) and the xylem is composed exclusively of scalariform
tracheids (x) and xylem parenchyma (Figure 7, 8).

The center of the solenostele is composed of parenchyma (pi) which
is much more uniform in nature than the cortex (Figure 6).

Notholaena brachypus (Kze.) J. Sm., Knobloch 1645.

The rhizome habit is short, thick and erect while the habitat is
damp, shaded banks, rocky places, on rocks and occurring from
200-1600 m.

The epidermis is present but was badly torn. Internal to the
epidermis (e) was a heavily-sclerified cortex (c) region. The abrupt
change to thinner walled cells in the cortex layers adjacent to the
outer endodermis (oen) (Figure 9) was distinct.

The outer endodermis (oen) is torn in this preparation, but the
inner endodermis (ien) is, for the most part, intact (Figure 9).
Internal to the endodermal layers are the outer and-inner pericycle

regions consisting of three to four cell layers.

81

Figure 9. N. brachygus. Complete rhizome
cross section, so enostele. X40.

82

 

83
Scattered Sieve cells and phloem parenchyma cells of both outer and
inner primary phloem lie on apposite Sides of the scalariform tracheids
of the xylem (x) (Figure 9). The pith (pi) region Shows no sclerifica-

tion except in one isolated area (Figure 9). Notholaena aurea is

 

interpreted to be a solenostele.

Notholaena ENNN1N3_(Mart. and Gal.) Hook. var. Ngggigg, Knobloch
2288.

The rhizome habit is short-creeping and branched, while the habitat
of this Species is on igneous rocks, found in sun or partial shade, from
500-1500 m. elevation.

In all sections examined, the most heavily sclerified regions of
the cortex (c) are outermost and the sclerification gradually decreases
as one progresses inward toward the outer endodermis (Figure 10). The
one-cell thick outer (oen) and inner (ien) endodermis were torn in some
preparations and not in others (Figure 11).

The outer pericycle (opc) is composed of three to four layers of
large parenchyma cells (Figure 11). An adventitious root (art) can be
seen originating in the outer pericycle (Figure 11) and the inner peri-
cycle (ipc) is of a similar composition (Figure 11).

t The outer and inner sieve cells are few in number and the phloem
parenchyma cells are adjacent to the xylem, while the xylem (x) is com-
posed of scalariform tracheids and xylem parenchyma is present (Figure
10, 12). Notholaena candida v. candida is considered to be soleno-
stelic (Figure 10). l

Notholaena candida (Mart. and Gal.) Hook. var.-Copelandii (C. C.
Hall) R. Tryon, McCulloch 14-71.

84

Figure 10. N, candida v. candida. Complete
rhizome cross section, solenostele. X40.
Figure 11. N. candida v. candida. Portion
of the vascuTar cylinaer. 2100.

85

 

86

Figure 12. N. candida v. candida. Cross
section of primary xylem. X400.

87

 

88

Figure 13. N, candida v. Copelandii. Com-
plete rhizome cross section, solenostele.
X40. Figure 14. N, candida v. Copelandii.
Portion of the vascular cylinder. X100.
Figure 15. N, candida v. Copelandii.
Longitudinal section of primary xylem.
X400.

89

 

90

The rhizome is short, compact, and multicipital. This variety of
N, candida occurs on limestone ledges and in crevices of canyon walls
and bluffs, on rocky slopes, at the base of cap rock and about boulders
up to 1117.6 m.

The cortex (c) is heavily sclerified except the two-three cell
layers adjacent to the outer endodermis (oen) (Figure 14). Both the
outer (oen) and inner (ien) endodermal layers were torn in this prepara-
tion (Figure 14). Internal to the endodermal layers the outer (opc) and
inner (ipc) pericycle were observed to consist of large parenchyma cells
with some type of food storage (f) material retaining a stain (Figure
14).

The outer (oph) and inner (iph) Sieve cells are scattered in a
single, sometimes double row and the phloem parenchyma is adjacent to
the xylem (x) (Figure 14). The xylem (x) is composed entirely of
scalariform tracheids and small scattered areas of xylem parenchyma are
visible (Figure 14, 15). The pith (pi) gradually increases in scleri-
fication as one proceeds toward the center (Figure 13). Notholaena
candida v. Copelandii exhibits a solenostele (Figure 13).

Notholaena cochisensis Goodding, Knobloch 2493.

The rhizome habit is short, thick, multicipital and densely clothed
with scales, and the habitat is rock outcrops, rocky slopes of limestone,
sandstone, lava and gypsum; usually found in full sunlight and occurring
up to 2,300 m. altitude.

Unfortunately the rhizomes were not in a very good state of preser-
vation for embedding and a high degree of tearing took place during

sectioning. The best sections are described and illustrated.

91

Figure 16. N, cochisensis. Complete rhizome
cross section, transitional. X40. Figure 17.
N, cochisensis. Complete rhizome cross sec-
tion, solenostele. X40. Figure 18. N,
cochisensis. Longitudinal section of primary
xylem. X400.

 

 

 

92

 

93

Figure 19. N. cochisensis. Stipe cross sec-
tion. X100. Figure 20. N. cochisensis.
Portion of the rhizome vascular cylinder.
X100.

 

 

94

 

95

The epidermis (e) is partially intact in this Species, and the
outer cortex (c) area can be seen to be heavily sclerified, with the
cells closest to the vascular cylinder being least sclerified (Figure
16). In a great many cases the cell lumens are entirely obscured.

Figure 17 is probably an older rhizome section than Figure 16,
this would be indicated by the greater degree of cell wall thickness
and a greater concentration of tannin-like substances.

In sections examined of this species the outer and inner endodermal
layers were torn. In Figure 20 the outer (opc) and inner (ipc) peri-
cycle tissues and an area where the outer endodermis (oen) is intact are
all visible.

The sieve cells and parenchyma of the phloem are more easily
discerned on the inner (iph) Side of the xylem (x), while the outer
sieve (oph) and parenchyma cells appear a bit compressed (Figure 20).
The xylem (x) consists of scalariform tracheids (Figure 18, 20), xylem
parenchyma can also be seen (Figure 20). The pith (pi) may be lightly
or heavily sclerified. Figure 16 shows the former and Figure 17 shows
the latter type.

Figure 16 illustrates a section that has two leaf gaps (lg)
occurring in it. One leaf trace (1t) is visible in Figure 19. Figure
17 shows the same tissue arrangements. The difference being the greater
degree of sclerification and that a true solenostele is present.
Notholaena cochisensis is a transitional stele type.

Notholaena Galeottii Fée, Knobloch 2198.

The habit of the rhizome is sub-horizontal and/or short-creeping.
The habitat is shaded or exposed rocks and rocky banks occurring from

1500-2200 m. elevation.

96

Figure 21. N, Galeottii. Complete rhizome
cross section, solenostele. x40. Figure 22.
N, Galeottii. Portion of the rhizome vas-
cular cy11naer. X100.

97

 

98

The epidermis (e) is partially torn off in the preparation, but is
partially seen as are rhizome Scales (sc) (Figure 21). Internal to
epidermis the outer third of the cortex (c) can be seen as sclerified
and the remainder of the cortex is less sclerified (Figure 21).

Figure 22 illustrates the three-four cell layered outer pericycle
(opc), Sieve cells and phloem parenchyma (oph) plus the xylem (x) which
is composed of scalariform tracheids and xylem parenchyma cells.

Figures 114, 115 illustrate isolated scalariform tracheids (x) and
Figure 116 illustrates a helical protoxylem cell (px). The pith area
is most heavily sclerified in the central portion (Figure 21).

This species is a solenostele. Even though the preparation of
this species is not ideal, all 35 sections examined indicated the
solenostele condition as being present.

Notholaena Nggxll Davenp., Knobloch 2078.

The rhizome is nodose, multicipital, sometimes short-creeping and
densely scaly. The habitat is talus slopes in rock crevices, barrens of
igneous rock and limestone occurring up to 1,900 m. altitude.

The epidermis and epidermal appendages are sclerified in this taxon.
Internally from the epidermis the cortex (c) is heavily sclerified
(Figure 23) with the exception of the innermost cell layers (Figure 24).
Both outer (oen) and inner (ien) endodermal layers have been torn in
this preparation (Figure 24), and the outer (opc) and inner (ipc) peri-
cycle regions are composed of large parenchyma cells (Figure 24).

The Sieve cells of both outer (oph) and inner (iph) primary phloem
are partially compressed and the phloem parenchyma cells are adjacent
to the xylem (Figure 24). The xylem (x) is composed of scalariform
tracheids and xylem parenchyma is present (Figure 24). An examination

99

Figure 23. N. Gra 1. Complete rhizome cross
section, solenoste e. x40. Figure 24. N.
Gra i. Portion of the vascular cylinder.
11100.

100

 

101
of all sections (14) of Notholaena Nggxii indicate a solenostele (Figure
23). A partially closed leaf gap (lg), a new leaf trace (1t) origi-
nating, and an adventitious root (art) originating from the outer
pericycle (Figure 23). The pith (pi) becomes more sclerified as one
progresses toward the center (Figure 23).

Notholaena integerrima Hook., McCulloch 61-71 and 31-71.

The rhizome is short, thick, multicipital and densely clothed with
hairs and the habitat is on calcareous substrates.

The epidermis (e) is intact in this preparation (Figure 25).
Internal to the epidermis, the cortex (c) has a very definitive outer
band of thickened cells and an inner region of relatively unsclerified
cells in which large air Spaces (as) occur (Figure 25). 1

The outer endodermis is partially torn but the inner endodermis is
intact. The outer and inner pericycle areas are similar to other taxa
examined, as are the sieve cells and phloem parenchyma cells of the
outer and inner primary phloem.

The xylem (x) is scalariform tracheids and there is xylem paren-
chyma present (Figure 25).

All sections examined illustrated the transitional and solenostele
condition. Figure 25 illustrates the solenostele condition, and three
adventitious roots (art) can be seen emerging from the outer pericycle.
The pith (pi) is uniform in composition with the same types of air
spaces (as) present as seen in the cortex (Figure 25).

Notholaena Lemmonii D. C. Eaton, Cross §:£:

The rhizome habit of this taxon is multicipital, short, thick, and

ascending.

102

Figure 25. N. integerrima. Complete rhizome
cross section, solenostele. x40.

 

103

 

104

Figure 26. N, Lemmonii. Complete rhizome
cross section, solenostele. X40. Figure 27.
N. Lemmonii. Portion of the vascular cylin-
Her. x100.

105

 

106

Figure 28. N. Lemnonii. Cross section of
primary xylem. X400.

107

 

108

The habitat of N, Lemmonii is the base of shaded rocks, pendent
from crevices of old stone walls and igneous rocks from 1000-1500 m.
elevation.

The epidermis (e) is partially torn in this preparation (Figure 26),
while the cortex (c) exhibits a band of heavily sclerified cells, a band
of lightly sclerified cells and a band of heavily sclerified cells as
one progresses from the epidermis inward to the outer endodermis (oen)
(Figure 26).

The outer (oen) and inner (ien) endodermal layers are both partially
torn (Figure 26), and the outer (opc) and inner (ipc) pericycle consist
of large parenchyma cells arranged in three to four cell layers
(Figure 27). An adventitious root (art) can be seen originating from
the outer (opc) pericycle in Figure 27. A leaf gap (lg) and leaf trace
(1t) are noted in the lower right hand portion of Figure 26.

The Sieve cells of the outer (oph) primary phloem forms a single
layer that is almost uninterrupted (Figure 27), whereas the inner pri-
mary phloem is compressed. Phloem parenchyma separates the sieve cells
from the xylem. The xylem (x) consists of scalariform tracheids, among
which are scattered areas of xylem parenchyma (Figures 27, 28). The
pith (pi) is uniformly heavily sclerified except for the outer one or
two cell layers (Figure 26). Notholaena Lemmonii exhibits a solenostele.

Notholaena limitanea Maxon var. mexicana (Maxon) Broun, McCulloch
59-71.

The rhizome habit is described as decumbent to horizontal and com-
pact and short. The habitat of this species is cliffs and rocky
hillsides in calcareous or acidic soils occurring from elevations of

109

Figure 29. N, limitanea v. mexicana. Com-
plete rhizome cross section, transitional.
x40. Figure 30. N, limitanea v. mexicana.
Portion of the vascular cylinaer, aavent1tious
root. x40. Figure 31. N, limitanea v.
mexicana. Cross section of tfie vascular
cy|1naer. X100. Figure 32. N, limitanea v.
mexicana. Outer endodermis to xylem. X400.

 

110

111

The epidermis (e) is partially torn in this taxa (Figure 29).

The cortex (c) is uniform in its composition of large parenchyma cells
which are for the most part not sclerified. In some areas toward the
epidermis, two to three cell layers of cortex show some sclerification
(Figure 29).

Both outer (oen) and inner (ien) endodermal areas are torn, except
in a few specific areas (Figure 31). The outer (opc) and inner (ipc)
pericycle areas consist of two to four cell layers of parenchyma cells
(Figure 31). The cells of both pericycle regions are smaller than the
parenchyma cells of the cortex. Adventitious roots (art) can be seen
originating from the outer pericycle (Figure 29, 30).

The primary phloem of both outer (oph) (Figure 31, 32) and inner
(iph) (Figure 31) areas are sieve cells which occur in practically a con-
tinuous band in the vascular cylinder. The phloem parenchyma, both
inner and outer, consist of cells smaller than the parenchyma of the
pericycle. The xylem (x) consists of presumably scalariform tracheids
and xylem parenchyma (Figure 31, 32). The pith (pi) is of similar com-
position to the cortex with little or no sclerification evident (Figure
30). All sections examined Showed neither a true solenostele nor a
true dictyostele. Therefore, N, limitanea v. mexicana is a transi-
tional stele.

Notholaena neglecta Maxon, McCulloch 85-71.

The rhizome habit is short, multicipital, decumbent and densely
scaly. The habitat is dry crevices in limestone ledges and cliffs and
on rocky slopes and in canyons.

The epidermis is partially torn off from this preparation. The
cortex (c) is uniform except for a few isolated areas that Show some

sclerified cells (Figure 33).

112

Figure 33. N, neNlecta. Complete rhizome
cross section, so enostele. X40. Figure 34.

N, ne lecta. Oblique section of primary
xylem. X400.

113

 

114

The one cell thick outer and inner endodermal areas are partially
torn in this preparation, while the pericycle, outer and inner, is a
region of four to five cell layers in thickness. An adventitious root
(art) is originating from the outer pericycle (Figure 33).

The sieve cells of the primary phloem (inner and outer) are scarce,
as in most species, and do not form a continuous band of cells. The
phloem parenchyma cells are scattered and adjacent to the xylem (x)
(Figure 34). The xylem (x) is composed entirely of scalariform tracheids
and xylem parenchyma (Figure 34). One leaf gap (lg) and its subtending
trace (1t) can be seen in Figure 33. The pith (pi) is uniform except
for some heavily sclerified cells in the center and an isolated pocket

of cells (Figure 33). Notholaena neglecta is described as a solenostele.

 

Notholaena Newberryi D. C. Eaton, Knobloch accession 71-16,
Hoover §:fl:

The rhizome habit is horizontal, branched and forming dense clumps,
while the habitat is dry rocky places and crevices of rock, occuring up
to 1300 m.

The epidermis (e) is, for the most part, still intact and is one
cell layer (Figure 35). The cortex (c) in all sections examined (145)
was practically all uniform and the cell walls were heavily sclerified
(Figure 35, 36). ‘

Both outer (oen) and inner (ien) endodermal layers were usually
torn in preparation but some sections did have intact endodermal layers
(Figure 35). The outer (opc) and inner (ipc) pericycle regions consist
of fbur to five layers of parenchyma cells (Figure 36).

The outer (oph) and inner (iph) phloem areas are one to two layers

of cells wide and seem to form almost a continuous band around the stele,

115

Figure 35. N. Newberri i. Complete rhizome
cross section, solenostLéle. X40. Figure 36.
N. Newberr i. Portion of the vascular cylin-
Her. X100.

 

116

 

117

Figure 37. N, NewberrNi. Complete rhizome
cross section, trans t onal. X40. Figure 38.

N. Newberr i. Complete rhizome cross section,
Sblenostele. X40.

118

 

119
except where gaps occur. There are not as many phloem parenchyma cells
in this species and the sieve cells appear closer to the xylem than in
other taxa. The xylem (x) is not as massive as in previous Species and
there is no xylem parenchyma present (Figure 36). The pith (pi) area is
heavily sclerified, with the least sclerified cells seeming to occur in
the central portion of the pith (Figure 36). Figures 35 and 38 indicate
that this taxon is a solenostele with some indication that-it may be
transitional (Figure 37) in some portions of its habit.

Notholaena pgrvifolia R. M. Tryon, Knobloch 1687 and 1687-1.

The rhizome habit is short, thick and scaly. The habitat of this
species is limestone ledges in gorges and canyons, high on limestone
hills and talus slopes, faces of cap rock, and in shaded or exposed
situations.

The epidermis (e) of the preparation is partially intact (Figure
39). 1687-1 illustrates a high degree of tissue disintegration in the
cortex (c) and pith (pi) regions (Figure 40). It still can be noted,
however, that two distinct areas exist in the cortex (c): an outer
band (4-5 cells in thickness), the cells of which have definitely more
sclerified walls and are smaller in area than those of the remaining
inner area (Figure 40). Figure 39 of collection 1687 shows the same
arrangement, but in this specimen there is no disintegration.

Endodermal areas are partially torn in 1687-1 and 1687, while peri-
cycle areas are most obvious in collection 1687, in which adventitious
roots (art) can be seen (Figure 39).

The sieve cells in the phloem areas, both outer and inner, are
similar to other taxa described, that is, they are few in number and

scattered in a ring surrounding the xylem. Figure 41 illustrates the

120

Figure 39. N, parvifolia. Complete rhizome
cross section, transitional. X40. Figure 40.
N, pprvifolia. Complete rhizome cross section,
transitionalil X40.

 

 

121

 

122

Figure 41. N. parvifolia. Cross section of
primary xylem. X400.

 

123

 

124
scalariform tracheids (x) and the xylem parenchyma. The pith (pi) is
homogenous throughout with no indication of sclerified cells (Figure 39).

Figures 39, 4O illustrate a good section that is transitional in
nature, therefore, N, parvifolia is considered to be transitional.

Notholaena N131N3_Davenp., Knobloch 2244.

The rhizome habit is horizontal and rather slender, and the
habitat is limestone ledges.

The one-celled layer of epidermis (e) is intact in this prepara-
tion and several scales can be seen in Figures 42 and 43. The cells of
the cortex (c) appear to be equally sclerified, but with smaller cells
toward the epidermis and inner endodermis (Figure 42, 44). All cells
are impregnated by suberin and lignin. The effect of the wall impreg-
nations is heightened by the filling of the cells in the cortex and
pith in this case, with gums and tannin-like substances.

Both outer (oen) and inner (ien) endodermal layers are torn in this
preparation (Figure 42). Both outer (opc) and inner (ipc) pericycle
regions are from one to four cells thick and consist of variously shaped,
thin-walled parenchyma cells and enclose food (f) reserve materials
(starches and oils) in addition to the normal cell contents (Figure 44).

The outer (oph) and inner (iph) primary phloem is readily visible
in Figure 44 and consists of a narrow band of sieve and phloem parenchyma
cells. The phloem parenchyma cells are smaller than those of the peri-
cycle but also contain reserve foods (f) (Figure 44). The xylem (x)
consists of scalariform tracheids and xylem parenchyma is present
(Figure 45). The pith (pi) cells have the same type of cell wall
impregnations and cell content as the cells of the cortex, the most

heavily sclerified area being the central mass of cells (Figure 42).

125

Figure 42. N, ri ida. Complete rhizome cross
section, solenoste e, internode. X40.
Figure 43. N, rigida. Complete rhizome cross
section with leaf trace at node. X40.

126

 

127

Figure 44. N, riaida. Portion of the vas-
cular cylinder. 00. Figure 45. N, ri ida.
Cross section from outer pericycle to primary
xylem. X400.

128

 

129
In all sections examined a solenostelic condition was noted, and
therefore, N, £12122.15 considered to be solenostelic.

Notholaena Schaffneri (Fourn.) Underw. ex Davenp. var. Schaffneri,
Knobloch 2478.

The rhizome is short, branched and ascending, and the habitat is
shaded ledges and rocky places from 100-1700 m. elevation.

The one-celled thick epidermis of this Species is still intact and
a portion of a rhizome scale (Sc) can be seen in Figure 46. In this
species the thickest-walled cells of the cortex occur in a central band
in the cortex bounded on the inside and outside by thinner-walled cells.
In many cases the lumen of the cells has been occluded by the cell con-
tent (c) (Figure 47).

Both outer (oen) and inner (ien) endodermal layers are torn in this
preparation (Figure 46). The root traces (art) can be seen originating
from the outer pericycle (0pc) in Figure 46. The leaf gap (lg) is still
present from the origin of a leaf trace (1t) and a second trace (1t)
appears to be forming (Figure 46). The outer (opc) and inner pericycles
are from three to four cells thick (Figire 47).

The sieve cells of the outer (oph) and inner (iph) primary phloem
were compressed in sectioning and appear as a thin dark line bordering
a large xylem (x) area consisting of scalariform tracheids and xylem
parenchyma cells (Figure 47). The pith (pi) of this species has the
same cellular banding arrangement as the cortex (Figure 46). N, NgNgff:
ENNj_is solenostelic.

Notholaena sinuata (Lag. ex Sw.) Kaulf., McCulloch 43-71.

The rhizome of this species is short, thick, multicipital and
densely clothes with scales, while the habitat is dry, gravelly slopes,

130

Figure 46. N, Schaffneri. Complete rhizome
cross section, three adventitious roots,
solenostele. x40. Figure 47. N, Schaffneri.
Portion of the vascular cylinder. XlOO.

 

131

 

132

Figure 48. N, sinuata. Complete rhizome
cross section, aaventitious root and leaf
trace. X40. Figure 49. N, sinuata. Por-
t10n of the vascular cylinder at lower right.
X 00.

133

 

134
with the plants being found on or about boulders, ledges and canyon
walls and in crevices of lava cliffs, in full sunlight or in partial
shade and up to 2000 m. altitude.

The epidermis (e) is intact in this preparation as evidenced by
the sclerified rhizome scales (sc) (Figure 48). The cortex (c) is
divided into two distinct areas; an outer region which is heavily scleri-
fied and the cells filled with tannin-like Substances and an inner
region, in which the cells are not nearly or not sclerified and seem to
have intracellular air spaces (Figure 48, 49).

The outer (oen) and inner endodermis are for the most part intact
(Figure 49). Starches and oils are visible in both the inner and outer
parenchyma cells of the pericycle and a root trace (art) can be seen
originating from the outer pericycle in Figure 48.

Sieve cells and parenchyma cells of the outer (oph) and inner (iph)
primary phloem are alike in appearance and visible in Figure 49. The
xylem (x) consists of scalariform tracheids and xylem parenchyma is
present (Figure 49). The pith (pi) resembles the cortex in cell types,
but not in arrangement. The more heavily sclerified cells seem to occur
at points of leaf trace origins (Figure 48). In all sections examined
a solenostele was observed.

Notholaena Standlezi Maxon, McCulloch 60-71.

The rhizome of N, Standleyi is short, multicipital and densely
covered with scales. The habitat is one of dry rock ledges and
crevices, on talus slopes, cliffs, canyon walls and on and among boul-
ders, on sandstone, limestone, rhyolite and lava, occurring up to

elevations of 2,200 m.

135

Figure 50. N, Standle i. Complete rhizome
cross section, adventitious root and leaf gap.
X40. Figure 51. N, Standlezi. Vascular
cylinder. X40.

136

 

137

Figure 52. N, Standlezi. Portion of the vas-
cular cylinder, at top. X100. Figure 53.

N, Standle i. Longitudinal section of primary
xylem sfiowing scalariform tracheids. X400.

138

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139

The epidermis (e) in N, Standlexi is still intact and several
rhizome scales (sc) can be seen in Figure 50. The cortex is very
heavily sclerified from the epidermis (e) to the outer endodermis (oen)
(Figure 50, 51). The cortical cells closeSt to the epidermis and outer
endodermis are the most heavily sclerified and the middle area of the
cortex has cells that are slightly less sclerified. In most cases the
cortical cell lumens are completely obscured (Figure 51).

The outer (oen) and inner (ien) endodermal layers were both torn in
this preparation (Figure 51). The outer (opc) and inner (ipc) pericycle
areas are alike, consisting of large, thin-walled parenchyma cells
(Figure 51).

Sieve cells and phloem parenchyma cells of both outer (oph) and
inner primary phloem areas are alike (Figure 52). The xylem (x) consists
of scalariform tracheids and xylem parenchyma is present (Figure 52).
Figure 53 illustrates the scalariform tracheids (x) in longitudinal
section and Figure 117 shows them (x) isolated after maceration. The
pith (pi) is evenly sclerified with most of the cell lumen areas obscured
(Figure 51).

This species is a solenostele with some areas that show a transi-
tional nature.

Table 6 is a list of Notholaena Species that have had the rhizome
described in the literature by various authors but were not available

for sectioning by this investigator.

140

 

 

 

 

TABLE 6. Stele types of unsectioned Notholaena rhizomes.
Species Stele Source
Marantae R. Br. transitional Gwynne-Vaughan (1903)
Br. transitional Ogura (1972)

N.

N, Marantae R.

N, Marantae R. Br.
R.

. Marantae Br.

N, trichomanoides (L.)
R. Br.

N, trichomanoides (L.)
R.*Br.

N, trichomanoides (L.)
R.’Br.

N, trichomanoides (L.)
R. Br.

dorsiventral soleno-
stele

dorsiventral dictyo-
Stele

transitional

transitional

transitional to
solenostele

dorsiventral dictyo-
stele

Tansley (1907)
Posthumus (1924, 1936)

Gwynne-Vaughan (1903)
Ogura (1972)
Posthumus (1936)
Posthumus (1924)

 

Table 7 summarizes the stale type and the presence or absence of

xylem parenchyma in the Notholaena Species examined. Table 8 sum-
marizes the number of sections examined and the stem diameter of the

rhizomes.

Pellaea allosuroides (Mett.) Hieron, Knobloch 2069.

The rhizome of N, allosuroides is rather stout, short-creeping and
densely scaly, and the habitat is cliffs, boulders and humus on rocky
slopes up to 2,600 m. elevation.

The epidermis (e) is partially sloughed off in these preparations
(Figure 54, 55). The cortex (c) is heavily sclerified with the outer
few cell layers being less so than the inner regions (Figure 55).

Both outer (oen) and inner (ien) endodermal layers have been torn
in preparation (Figure 55). The outer and inner pericycle regions are

thin-walled, parenchyma cells. Adventitious roots (art) can be seen as

141

TABLE 7. Stele type and xylem parenchyma of Notholaena.

 

 

 

 

 

 

 

 

 

 

 

 

Species Xylem parenchyma Stele
N, Aschenborniana no solenostele
N, EEESE. yes solenostele
N, brachzgus yes solenostele
N, candida v. ggggjgg_ yes solenostele
N, candida v. Copelandii yes solenostele
N, cochisensis yes solenostele-transitional
N, Galeottii yes solenostele
N, 953;; yes solenostele
N, integerrima yes solenostele-transitional
N, Lemmonii yes solenostele
N, limitanea v. mexicana yes transitional-solenostele
Np neglecta yes solenostele
N, Newbergyi no solenostele-transitional
N, parvifolia yes transitional
N. {131511 yes solenostele
N, Schaffneri yes solenostele
N, sinuata yes solenostele
N, Standlexi yes solenostele

 

142

 

 

 

 

TABLE 8. Number of sections examined and stem diameter of Notholaena.
jicti ons Rhizome
5999195 examined diameter (11111.)
N. Aschenborniana 14 2.50 - 3.50
N. M 41 3.75 - 5.00
N. brachygus 1 3.50 - 5.00
N. £92119}. v. g_a_p_d_ig_a_ 77 2.00 - 3.50
N. M v. Copelandii 13 1.10 - 1.25
N. cochisensis 42 2.50 - 4.00
N. Galeottii 35 2.00 - 2.25
N. N911 14 2.00 - 3.00
N. integerrima 18 3.00 - 4.25
N. Lenlnonii 3 1.25 - 2.25
N. limitanea v. mexicana 8 3.50 - 4.50
N, neglecta 6 1.50 - 2.00
N. Newberryi 145 1.25 - 2.00
N, parvifolia 99 5.50 - 6.00
N. r_ig_1_d_g 97 1.50 - 1.75
N. Schaffneri 44 2.00 - 3.00
N. M 3 3.00 - 4.00
N. Standlezi 10 2.00 - 2.75

 

 

 

 

 

 

 

143

Figure 54. N, allosuroides. Complete vascu-
lar cylinder with—leaf gap, leaf trace and
adventitious root, solenostele. X40.

Figure 55. N, allosuroides. Complete vascu-
lar cylinder, leafigap anditwo adventitious
roots, solenostele. X40.

 

144

 

145

Figure 56. N, allosuroides. Cross section
of primary xylem. X400.

 

146

 

147
originating from the outer pericycle area in Figure 54, 55 and a leaf
gap (lg) and leaf trace (1t) are visible in Figure 54.

The sieve cells and parenchyma cells of the outer and inner primary
phloem have been compressed in preparation and appear as a thin, dark
line in both outer and inner areas. The xylem (x) is scalariform tra-
cheids and it should be noted that no xylem parenchyma is present
(Figure 55, 56). The pith (pi) is very highly sclerified and the cell
contents occlude the lumens as it does in the majority of cells in the
cortex (Figure 55). All sections examined illustrated a solenostele
(Figure 54, 55).

Pellaea andromaedifolia (Kaulf.) Fee, Knobloch accession 71-22.

The rhizome is slender, cord-like, dichotomously branched, long-
creeping and rarely compact. The habitat of this fern is dry, rocky
ravines, ledges or along moist shaded stream banks between 60-100 m.
elevation.

The epidermis (e) is intact (Figure 57, 58) and numerous rhizome
scales (sc) are visible in this preparation (Figure 57). The cortex (c)
illustrates a distinct banding pattern: in the outer region a layer,
8-10 cells thick, that are unsclerified with tannin-like substances
present in their cells; the middle region consisting of a layer eight
cells in thickness that are rather heavily sclerified with tannin-like
substances in their cells; and an inner 3-5 cell layer of cells Similar
to the outermost region (Figure 57, 58).

The outer (oen, Figure 58) and inner (ien, Figure 57) endodermis
can be discerned as intact in many areas of the rhizome. Outer (oph)
and inner (iph) sieve cells and phloem parenchyma cells are readily seen

(Figure 58) and the xylem (x) consists of scalariform tracheids (Figure

148

Figure 57. N, andromaedifolia. Complete rhi-
zome cross section withleaf gap, solenostele.
X40. Figure 58. N, andromaedifolia. Portion
of rhizome from cortex to inner primary
phloem. XlOO.

149

 

150

Figure 59. N, andromaedifolia. Inner cortex
to primary xylem. X400.

151

 

152
58, 59). Xylem parenchyma is present (Figure 58, 59). All sections
examined illustrated a solenostelic condition, with some tendency
toward a transitional condition in a few sections.

The pith (pi) consists of an outer region of non-sclerified cells
and a large central mass of sclerified cells (Figure 57).

Pellaea atrgpurpurea (L.) Link, Knobloch accession 71-30, McCulloch
78-71.

The rhizome is short, densely clothed with long-attenuate, tortuous
rusty scales. The habitat is a rocky loam forest floor, rock ledges,
among rocks, on cliffs, canyon walls, banks and talus slopes of limerock,
occurring in partial shade and up to 2000 m. elevation.

The epidermis (e) is partially intact in this preparation (Figure
60). The cortex (c) shows no marked sclerification pattern in that all
cells seem to be unlignified (Figure 60). They contain some tannin-like
substances. .

The outer (0pc) and inner (ipc) pericycles are thin-walled paren-
chyma cells two to four cell layers thick (Figure 62). The sieve cells
and phloem parenchyma cells of the outer (oph) and inner (iph) primary
phloem are evident (Figure 62).

The xylem (x) consists of scalariform tracheids (Figure 62, 63)
and xylem parenchyma is present (Figure 62). An isolated scalarifbrm
tracheid (x) can be seen in Figure 118. Figure 119 illustrates a
helical protoxylem (px) cell. The pith (pi) has the same cellular com-
position as the cortex (Figure 60, 61, 62). The majority of sections
examined illustrated a solenostele (Figure 60) with some sections being

transitional (Figure 61).

153

Figure 60. N, atropurpurea. Complete rhizome
cross section, one leaf gap, one leaf trace
and adventitious root. X40. Figure 61. N,
atropurpurea. Vascular cylinder, two leaf
gaps, tranSitional. X40.

 

 

154

 

155

Figure 62. P. atropurpurea. Portion of the
vascular cylinder—in center. X100.

Figure 63. N, atggpurpurea. Longitudinal
section of primary xylem, scalariform tra-
cheids. X400.

 

 

156

 

157
‘ Pellaea brachyptera (Moore) Baker, Knobloch accession 65-13.

The rhizome is moderately stout, elongate, decumbent and/or multici-
pital, while the habitat of this species is talus slopes, basalt or
serpentine rock outcrops from 800-2900 m. elevation.

The epidermis (e) of this species is intact (Figure 64, 65). The
cortex (c) consists of two distinct regions: the outer region is three
to four cell layers thick and are very sclerified, with the cell lumens
obscured by tannin-like substances; the inner region is much less scleri-
fied but the tannin-like substances are still present (Figure 64, 65).

Both the outer (oen) and inner (ien) endodermis are partially torn
in this preparation (Figure 64, 65). The outer and inner pericycle,
Sieve cells and phloem parenchyma cells, both outer and inner, are par-
tially or wholly disrupted and/or compressed.

The xylem (x) consists of the usual scalariform tracheids and xylem
parenchyma is present (Figure 66). The pith (pi) is loosely organized,
especially in its center, some cells are, however, sclerified (Figure 64,
65).

This specimen was interesting because of the high degree of varia-
tion in the vascular cylinder. This species is described as being
solenostelic (Figure 64), with Figure 65 illustrating the transitional
condition which was found in some sections. Two leaf gaps (1g) and two
leaf traces (1t) are readily seen in Figure 65.

Pellaea Breweri D. C. Eaton, Knobloch accession 71-29, E. Taylor
§,N,

The rhizome of this specimen is compact, ascendent, massive and
with many compressed bases of articulated stipes and a habitat of
usually granite rocks or basalt, but also on limestone and occuring at

elevations from 1600-3800 m.

158

Figure 64. N, brachyptera. Complete rhizome
cross section, aHVentitious root, solenostele.
X40. Figure 65. P. brachyptera. Complete
rhizome cross section, two leaf gaps, two leaf
traces, adventitious root, transitional. X40.

 

 

159

 

160

Figure 66. N. brachygtera. Cross section of
primary xylem. Y400.

 

161

 

162

The one-cell thick epidermis (e) in this taxa is for the most part
intact (Figure 67). The cortex (c) (Figure 67, 68), except for the
outermost one, two or three cell layers, is uniform in sclerification.
The parenchyma cells of the cortex retain a food storage material
besides the normal cell contents.

Figure 69 illustrates the intact outer (oen) and inner (ien) one-
celled thick endodermal areas. Because of the fragility of the tissue
it is often torn in sectioning as seen in some areas.

The outer (opc) and inner (ipc) pericycle (Figure 69) areas are both
composed of thin-walled parenchyma cells that retain food (f) storage
materials. Both pericycle tissue areas are from two to four cells thick
and the cells are generally smaller than the cells of the cortex.

The sieve cells, both outer (oph) and inner (iph), of the primary
phloem are readily visible in Figure 69. Primary phloem areas can
generally be distinguished in cross section because the Sieve cells are
angular in cross section and usually lack any stainable cell contents.
For the most part the sieve cells form a continuous band in the vascular
system. The outer and inner phloem areas also consist of parenchyma
cells which are Smaller than the pericycle cells.

The xylem (x) consists of scalariform tracheids (Figure 69, 70)
and xylem parenchyma. The pith (pi) is similar, in cell composition and
uniformity, to the cortex. There are no sclerified areas in the pith
(Figure 67). Figure 67 illustrates a transitional type stele where four
gaps (lg) and four leaf traces (1t) are visible. An adventitious root
(art) can be seen originating from the outer pericycle in Figure 67, 68.

Most sections examined were solenostelic. Therefore, N, Breweri is
considered to be solenostelic with some portions of the rhizome being

transitional.

163

Figure 67. N, Breweri. Complete rhizome
cross section, four leaf gaps, four leaf
traces, adventitious root, transitional. X40.
Figure 68. N, Breweri. Portion of the vascu-
lar cylinder, aaventitious root, xylem. X40.

164

 

165

Figure 69. N, Breweri. Portion of the vas-
cular cylinder in center. X100. Figure 70.

N, Breweri. Oblique section of primary xylem.
400.

166

’0
\o
O 4.0

’l..\
'L
'
'C

.0
or...

t

 

167

Pellaea Bridgesii Hooker, Knobloch accession 71-26, R. Rodin £35?

The rhizome is short-creeping, often massive and with the divisions
short and close.

The epidermis (e) is intact and remains of the rhizome scales are
present (Figure 71). The cortex (c) region is unsclerified except for
the outermost two-three layers (Figure 71). Tannin-like Substances are
easily visible in the cells of both the cortex (c) and pith (pi)

(Figure 71, 72, 74).

Both endodermal areas (outer, oen and inner, ien) are intact except
for small tears in the outer endodermis (Figure 72). The outer (0pc)
and inner (ipc) pericycle are composed of thin-walled parenchyma cells
(Figure 72). An adventitious root can be seen in Figure 74.

The outer (oph) and inner (iph) sieve cells and phloem parenchyma
:are readily visible in Figure 72. The xylem (x) presumably consists of
'Scalariform tracheids and xylem parenchyma (Figure 72, 73). The pith
(pi) is similar to the cortex except there are no sclerified cells
(Figure 74). This species would be considered to be a solenostele
(Figure 71) but with some sections transitional. In Figure 74 two leaf
gaps (lg) are visible and one leaf trace (1t).

Pellaea dealbata (Pursh) Prantl, Knobloch accession 72-4, Seigler
1035.

The rhizome is short and ascending, and the habitat is dry crevices
on cliffs and boulders of limestone and other calcareous rocks and
usually occurring in partial shade.

The epidermis (e) is intact in this preparation as can be seen in
Figure 75, 76. The cortex (c), directly beneath the epidermis, has
three-five layers of cells that are filled with tannin-like substances

168

Figure 71. N, Bridgesii. Complete rhizome
cross section, one leaf gap, solenostele.

X40. Figure 72. P. Brid esii. Portion of
the vascular cylinaer in tfie center. X100.

169

 

170

Figure 73. P. Brid esii. Cross section of
primary xylefil X408. Figure 74. P.

Brid esii. One leaf gap, leaf tracE, adven-
titious root, solenostele. X40.

171

 

172

Figure 75. N, dealbata. Complete rhizome
cross section, aictyostele. X40. Figure 76.
N, dealbata. Portion of the rhizome from
epiaermis to pith. X100.

173

 

174

Figure 77. N, dealbata. Portion of vascular
cylinder or meristele. XlOO. Figure 78. N,
dealbata. Longitudinal section of primary
xylem, prominent scalariform tracheids. X400.

175

 

176
with the remainder of the cortex being composed of large, unsclerified
cells (Figure 76).

Both outer (oen) and inner (ien) endodermal layers consist of rec-
tangular cells and they are torn in some areas in this preparation
(Figure 76, 77). The outer (0pc) and inner (ipc) pericycles are two-
three cells in thickness and are smaller than the cortical cells but
have the same Shape (Figure 76, 77).

‘The outer (oph) and inner (iph) sieve cells and phloem parenchyma
are similar in their distribution and occurrence to previous taxa and
can be seen in Figure 76, 77. The xylem (x) consists of scalariform
tracheids (Figure 77, 78) and xylem parenchyma (Figure 77). The pith
(pi) is of the same general composition as the cortex, except that there
are no distinct areas of tannin-filled cells (Figure 75, 76). This
species is considered to be a dictyostele (Figure 75).

Pellaea falcata (R. Br.) Fée, Knobloch accession 72-7.

The epidermis (e) is partially intact in this preparation (Figure
79). The cortex (c) has a band of several layers of highly sclerified
cells in the central region. The cell lumens are completely obscured
with tannin-like substances in most cases. The thick cell walls are
impregnated with lignin and suberin. The layers of cells outward from
the central band appear to have very little sclerification (Figure 79,
80). The cell layers inward appear to have some degree of sclerifica-
tion, but lack the large amounts of tannin-like substances (Figure 80).

Both outer (oen) and inner (ien) endodermal layers are torn in most
areas (Figure 80). There is very little pericycle in this species,
usually two-three cell layers in both outer (opc) and inner (ipc) regions
(Figure 80). Figure 80 illustrates an adventitious root (art) origi-

nating at the arrow.

177

Figure 79. N, falcata. Complete rhizome
cross section, one leaf gap, solenostele.
X40. Figure 80. N, falcata. Vascular
cylinder and adventitious root. X40.

178

 

179

The outer and inner sieve cells of the primary phloem and phloem
parenchyma cells are similar to other taxa examined. The xylem (x) con-
sists of scalariform tracheids (Figure 80), and no xylem parenchyma is
present. The majority of the pith (pi) is composed of highly sclerified
cells with a band of three-four cells toward the inner endodermis that
are not sclerified (Figure 79, 80).

This Species exhibits a true solenostele.

Pellaea intermedia Mett. ex Kuhn, McCulloch 57-71.

The rhizome is elongate, Slender, widely-creeping, wirey, scaly and
about 1.5 cm. in diameter. The habitat is dry and rocky slopes and
ledges, cliffs and about boulders of igneous and limestone.

The epidermis (e) of this species is intact and some partial rhi-
zome scales (sc) can be identified in Figure 81, 82. The cortex (c)
region becomes more sclerified as one advances inward, with the excep-
tion of the last one or two cell layers that are adjacent to the outer
endodermis (oen) (Figure 82). No tannin-like substances can be observed.

The outer (oen) and inner (ien) endodermis are torn in this prepara-
tion (Figure 82). The outer (0pc) and inner (ipc) pericycle are similar
to each other in composition, both consisting of thin-walled parenchyma
cells that stain fOr a food reserve substance in the cell along with the
normal cell content (Figure 82, 83).

Both outer (Oph) and inner (iph) sieve cells of the primary phloem
and the phloem parenchyma are readily visible in Figure 83. The xylem
(x) consists of scalariform tracheids and xylem parenchyma is present
(Figure 83). An isolated scalariform tracheid can be Seen in Figure
120. The pith (pi) becomes more sclerified as you move toward the cen-
ter (Figure 82). In all sections examined, this species demonstrated a

solenostele (Figure 81).

180

Figure 81. N, intermedia. Complete rhizome
cross section, internode. solenostele. X40. "
Figure 82. P. intermedia. Portion of the
rhizome. X100.

 

 

181

.... .\’.- '

I". ‘ 09‘
....1..’ 'r"
‘;"-.VO"2 oen

I

 

182

Figure 83. N. intermedia. Portion of vascu-
lar cylinder, note XYTem parenchyma. X400.

 

183

 

184

Pellaea longimucronata Hook., McCulloch 89-71.

 

The rhizome of this Species is described as being moderately stout,
elongate, decumbent and multicipital. This species occurs in clefts of
igneous rocks, among granite boulders in open sun, and in gravelly soil,
from 600-2000 m. elevation.

The epidermis (e) is partially intact, although it is difficult to
determine because of the heavy sclerification that is present in the
outer portion of the cortex (c) (Figure 87).

The outer (oen) and inner (ien) endodermis in Figure 84 are visible
even though they are partially torn. The outer (opc) and inner (ipc)
pericycle regions can be seen in Figure 84 and are from two to three
cells in thickness.

The outer (0ph) and inner (iph) sieve cells and phloem parenchyma
as well as scalariform tracheids (x) and xylem parenchyma are easily seen
in Figure 84. Figure 85 Shows a longitudinal section of the xylem (x)
area, in which the Scalariform nature of the tracheids can be seen. The
cells of the pith (pi) in this specimen are unsclerified (Figure 87).

In Figure 86 a rare occurrence was noted. It appears that an adven-
titious root (art) was growing through the pith (pi) area. This was
noted in all sections from this particular block and was not noted in
other blocks of the same Species.

Figure 87 illustrates a solenostelic condition with an adventitious
root (art) originating from the outer pericycle, and Figure 88 illus-
trates a transitional condition in which two leaf gaps (lg) and two leaf
traces (1t) can be seen. This Species is considered to be solenostelic

with scattered areas being transitional.

185

Figure 84. N, longimucronata. Portion of
the vascular cylinder with adventitious root.
X100. Figure 85. P. longimucronata. Lon-
gitudinal section of pFimary xylem, showing
scalariform tracheids. X400.

186

 

187

Figure 86. N, longimucronata. Vascular
cylinder with adventitious root in pith area.
X100. Figure 87. N, longimucronata. Com-
plete rhizome cross section, one leaf gap,
adventitious root, solenostele. x40.

188

 

189

Figure 88. N, longimucronata. Complete rhi-
zome cross section, two leaf gaps, two leaf
traces, adventitious root, transitional. X40.

 

190

 

191

Pellaea mucronata (D. C. Eaton) D. C. Eaton var. californica

 

 

(Lemmon) Munz and Johnston, Knobloch accessions 71-18 and 71-21, Rodin
§,N,

This species occurs on talus, among loose rocks or in rocky woods,
in shade or open sun and from 1800-3000 m. elevation.

The epidermis (e) in Figure 89 is partially intact. The specimen in
Figure 90 taken from another rhizome of the collectiOn has a more poorly
preserved epidermis, but both illustrate the same cortex (c) structure.
In both Figure 89 and 90 the sclerified layers of cortex cells occur
toward the outside and the remaining cells of the cortex are not scleri-
fied, or at least not sclerified to the same degree. Both specimens Show
tannin-like substances within the cells.

In both preparations the outer and inner endodermis is, for the
most part, intact. Figure 91 illustrates the vascular cylinder in which
the outer (0pc) and inner (ipc) pericycle regions are present and the
outer (oph) and inner (iph) sieve cells and phloem parenchyma cells of
the phloem. Specifically, the phloem area and pericycles show some
degree of compression from sectioning.

The xylem (x) consists of scalariform tracheids and xylem parenchyma
is present (Figure 91). The pith (pi) shows little or no sclerification
(Figure 92). This species illustrates a great deal of variation in the
vascular cylinder. Very few sections examined illustrated a true soleno-
stele, the majority of sections being transitional in nature (Figure 89,
90, 91, 92). No sections illustrated a true dictyostele, where the vas-
cular cylinder was completely dissected into meristeles. Figure 92
comes closest to resembling a dictyostele, where a number of meristeles

and leaf gaps (lg) can be seen on the upper right half of the vascular

192

Figure 89. N, mucronata v. californica. Com-
plete rhizome cross section, four leaf gaps,
transitional. X40. Figure 90. N, mucronata
v. californica. Complete rhizome cross sec-
tion, three leaf gaps. transitional. X40.

 

 

193

 

194

Figure 91. N, mucronata v. californica. Vas-
cular cylinder, two leaf gaps, transitional.
X100. Figure 92. P. mucronata v. califor-
nica. Vascular cylinder, four leaf gaps,
transitional. XlOO.

 

195

 

196
cylinder. The leaf traces are not visible. A number of sections
illustrated two meristeles.

Pellaea notabilis Maxon, McCulloch 79-71.

The rhizome is moderately stout, compact, decumbent and multicipital
and occurs among limestone rocks, along the banks of a stream and in
Shaded areas.

The epidermis (e) is intact (Figure 93), and the cortex (c),
excluding the outermost one-four layers of cells, is unsclerified (Figure
93, 95). Very little tannin-like substances appear in the parenchyma
cells of the cortex.

The outer (oen) and inner (ien) endodermis is intact (Figure 94).
Both outer and inner pericycle regions, sieve cells and phloem parenchyma
are present but hard to distinguish. An adventitious root (art) can be
seen in Figure 94.

The xylem (x) contains scalariform tracheids and xylem parenchyma
(Figure 94). The vascular cylinder for this taxon would be described as
transitional (Figure 93, 94) with some solenostelic sections (Figure 95).
The pith (pi) is unsclerified and resembles the cortex is composition
(Figure 94).

Pellaea gngg_(Desv.) Weatherby, McCulloch 76-71.

The rhizome is Slender, dichotomously branched, creeping or compact,
clothes with scales and enveloped by matted roots. ‘N, ggggg_may be
f0und on dry ledges and talus slopes of limestone, calcareous rocks or
granite, at the base of cliffs, in rich soil, brushy savanah, oak foreSts
in open sun or shaded banks.

'The epidermis (e) in this Species is partially intact and can be
seen in Figure 96, 97, and the cortex (c) is for the most part heavily

197

Figure 93. N, notabilis. Complete rhizome
cross section, tfiree leaf gaps, adventitious
root. X40. Figure 94. N, notabilis. Vas-
cular cylinder, transitional, leaf traces not
visible. X100.

 

198

 

199

Figure 95. N, notabilis. Complete rhizome
cross section, one leaf gap, solenostele.
X40.

200

 

201

Figure 96. P. ovata. Complete rhizome cross
section, one—leaf ga , adventitious root,
solenostele. X40. Figure 97. N, ovata.
Portion of rhizome. X100.

202

 

 

203

Figure 98. N, ovata. Oblique section of
primary xylem. i400. Figure 99. P. ovata.
Portion of the vascular cylinder. X100.

204

 

 

205
sclerified, except directly below the epidermis (Figure 97) and near the
outer endodermis (Figure 97, 99). The cell walls are impregnated with
suberin and lignin. The cell lumens are partially or totally obscured
in many areas of the cortex.

The outer (oen) and inner (ien) endodermal regions are partially
torn as can be seen in Figure 97. In Figure 99 the outer (0pc) and
inner (ipc) pericycle, the sieve cells (oph, iph) and phloem parenchyma
cells, tracheids (x) and xylem parenchyma are all clearly visible. Food
(f) storage material can be seen in the pericycle in Figure 99, and an
adventitious root is originating in the outer pericycle in Figure 96.

Figure 98 illustrates an oblique section through the xylem area and
the scalariform nature of the tracheids (x) can be seen. All sections
examined illustrated a solenostele (Figure 96). The pith (pi) fellows
the same general pattern of sclerification as the cortex (Figure 96).

Pellaea Eteroides (L.) Prantl, Knobloch accession 73-6, Schelpe
§,N,

The epidermis (e) is mostly sloughed off in this preparation
(Figure 100). The outermost five-six layers of cortex (c) are highly
sclerified, the remainder of the cortex is uniform in terms of cell wall
thickness and tannin-like substances are easily visible (Figure 100).

The outer (oen) and inner (ien) endodermis are partially intact
(Figure 101). The outer (opc) and inner (ipc) pericycle bear a distinct
resemblance to the cortical cells, as they also contain tannin-like Sub-
stances and the cells are of similar size (Figure 101).

Outer (oph) and inner (iph) sieve cells and phloem parenchyma are
readily distinguished (Figure 101). The phloem parenchyma cells also

contain what appear to be tannin-like Substances (Figure 102).

206

Figure 100. N, pteroides. Complete rhizome
cross section, two ea gaps, adventitious

root. X40. Figure 101. N, pteroides. Por-
tion of rhizome. X100.

207

 

208

Figure 102. P. teroides. Portion of the
vascular cylifider. X100. Figure 103. N,

pteroides. Vascular cylinder. XlOO.

209

 

210

The xylem (x) consists of scalariform tracheids and xylem parenchyma
(Figure 101, 102). In no sections was a true solenostele observed, so
this species is described here as a dictyostele (Figure 100, 103). The
pith (pi) has a composition Similar to the cortex but with the most
heavily sclerified cells occupying the central area (Figure 103).

Pellaea Skinneri Hook., Knobloch 2089.

The rhizome of N, Skinneri is Short and stout with a widespread root
system and the habitat is deep shade at the base of rhyolitic cliffs.

The epidermis (e) in this preparation is partially sloughed off
(Figure 104). The cells of the cortex (c) seem to be evenly sclerified
for the most part (Figure 104).

The outer (oen) and inner (ien) endodermis is torn (Figure 104),
and the outer (opc) and inner (ipc) pericycle contain some tannin-like
subStances (Figure 104). .

The sieve cells and phloem parenchyma are present as is usual but
the outer primary phloem area is more extensive than the inner primary
phloem area.

The xylem (x) consists of supposed scalariform tracheids. There is
no xylem parenchyma present in this species (Figure 104). All sections
that were examined had a solenostele (Figure 104). The pith (pi) seems
to.be uniformly sclerified with the exception of the outermost one or
two cell layers (Figure 104).

Pellaea viridis (Forsk.) Prantl var. viridis, Knobloch accession
number 71-33.

The epidermis (e) (Figure 105) is one-celled thick and intact for
the majority of the rhizome diameter. No stomata were noticed in our

preparations. The outer third to one-half of the cortex (c) is heavily

211

Figure 104. N, Skinneri. Complete rhizome
cross section, internode. solenostele. X40.

212

 

213

Figure 105. N, viridis. Complete rhizome
cross section, adventitious roots, three leaf
gaps. X40. Figure 106. N, viridis. Com-
plete rhizome cross section, aaventitious
roots, two leaf gaps. X40.

214

 

215

Figure 107. P. viridis. Portion of rhizome,

cross section. 2100. Figure 108. N, viridis.
Meristele, note prominent endodermis. X100.

216

 

217

Figure 109. N, viridis. Longitudinal sec-
tion of primary xylem, with scalariform
tracheids. X400.

 

218

 

219

sclerified and the inner portion is less sclerified or unsclerified
(Figure 105, 106). The degree of sclerification seems to vary with the
age of the Specimen.

The endodermis (oen, ien) is readily seen in this preparation as
de-limiting the stele in Figure 105. The endodermis is seen to be com-
posed of a one-celled wide layer with Casparian strips (Figure 107) on
the radial walls. The outer endodermis constitutes the innermost layer
of the cortex.

The outer and inner pericycles have several layers of thin-walled
parenchyma cells. The cells are of various shapes. The outer (0pc)
pericycle can be seen in Figure 107. In Figure 105, 106 adventitious
roots (art) can be seen originating from the outer pericycle.

The outer (oph) and inner primary phloem is composed of narrow
bands of sieve and parenchyma cells (Figure 107). The phloem paren-
chyma cells are smaller than those of the pericycle and can be seen in
Figure 107.

The primary xylem (x) consists of scalariform tracheids (Figure
108, 109) and xylem parenchyma is present (Figure 108). In Figure 121
an isolated scalariform tracheid (x) is visible. This species is
considered to be a dictyostele (Figure 105, 106). Figure 108 illus-
trates a meristele.

Pellaea X Wrightiana Hook., Knobloch 1624.

The epidermis (e) is partially intact and scales are visible
(Figure 110). The cortex (c) consists of an outer region of compact
cells four or five layers in thickness (Figure 110). The inner region
of the cortex consists of loosely arranged parenchyma cells (Figure 110,

113). The cells of the cortex do not appear to show any sclerification.

220

Figure 110. N, X Wrightiana. Complete rhi-
zome cross section, sOlenostele. X40.
Figure 111. P. X Wrightiana. Vascular
cylinder, one—leaf gap, solenostele. X40.

221

 

222

Figure 112. P. X Wrightiana. Longitudinal
section of primary xylem. X400. Figure 113.

P. X Nri htiana. Portion of the vascular
Eylinaer. 2100.

 

223

 

 

224

Both the outer (oen) and inner (ien) endodermal layers are intact
(Figure 113). The outer (opc) and inner (ipc) pericycle regions consist
of two to three layers of parenchyma cells which are smaller in Size than
the parenchyma cells of the cortex, yet larger than the phloem parenchyma
(Figure 113). An adventitious root (art) can be seen originating from
the outer pericycle in Figure 110.

The sieve cells of both outer (oph) and inner (iph) primary phloem
are readily visible, as in other taxa examined, and are few in number
(Figure 113). The outer (oph) and inner (iph) phloem parenchyma cells
are visible in Figure 113.

The xylem (x) consists of scalariform tracheids and xylem parenchyma
(Figure 112, 113). This species is considered to be solenostelic (Figure
110) with indications of being transitional in some sections. The pith
(pi) is of similar structure and composition as the inner region of the
cortex (Figure 110).

The vascular cylinders of three Notholaena and three Pellaea Species
were treated with Jeffrey's maceration liquid and observations made on
the xylem components.

Table 9 summarizes the stele type and the presence or absence of
xylem parenchyma in the Pellaea species examined.

Table 10 represents the number of sections of Pellaea examined and
the stem diameters.

Three samples of N, Galeotti illustrate scalariform tracheids (x)
(Figure 114, 115) and what appears to be a helical protoxylem (px)
tracheid (Figure 116). Two samples of N, Njgjgg_illustrate scalariform
tracheids, while three samples of N, Standleyi illustrate scalariform
tracheids (x) (Figure 117).

225
Pellaea atropurpurea, in three samples, illustrate scalariform
tracheids (x) (Figure 118) and what appears to be a helical protoxylem
(px) tracheid (Figure 119).

226

Figure 114. N, Galeottii. Scalariform tra-
cheid. X400. Figure 115. N. Galeottii.

Scalariform tracheid.

X400..-

——-—..-—~———-, A _

 

 

 

227

 

 

 

228

Figure 116. N. Galeottii. Helical proto-
xylem tracheial 7400. Figure 117. N.
Standleyi. Scalariform tracheid. X400.

 

 

229

 

 

 

230

Figure 118. P. atro ur urea. Scalariform
tracheid. X400. Figure 119. P. atro ur-
Eurea. Helical protoxylem tracfiei . 00.

 

 

 

231

 

 

 

232

 

 

 

 

 

 

 

 

 

 

TABLE 9. Xylem parenchyma and stele type of Pellaea.

Species Xylem parenchyma Stele
N, allosuroides no solenostele
N, andromaedifolia yes solenostele
N, atropurpurea yes solenostele
N, brachyptera yes solenostele
N, Breweri yes solenostele
N, Bridgesii yes solenostele
N, dealbata yes dictyostele
N, falcata no solenostele
N, intermedia yes solenostele
N, longimucronata yes solenostele
N, mucronata v. californica yes transitional
N, notabilis yes transitional
N, gngg_ yes solenostele
N, Eteroides yes dictyostele
N, Skinneri no solenostele
N, viridis v. viridis yes dictyostele.
N, X Nrightiana yes

 

solenostele

 

233

TABLE 10. Number of sections examined and stem diameter of Pellaea.

 

 

 

 

 

 

 

 

 

 

Sections *Rhizome
Species examined diameter (mm.)
N, allosuroides 24 1.25 - 1.50
N, andromaedifolia 33 1.50 - 1.75
N, atropurpurea 51 5.25 - 9.00
N; brachyptera 71 3.50 - 3.75
N, EIEEEEL. 67 4.00 - 5.00
N, Bridgesii 5 2.10 - 3.00
N, dealbata 39 3.00 - 3.50
N5 IEQEEEE. 21 2.00 - 2.50
N, intermedia 13 . 0.80 - 0.90
N, longimucronata 19 2.00 - 2.25
N, mucronata v. californica 18 4.00 - 4.50
N, notabilis 29 2.50 - 7.50
N, NNNNN_ 14 2.50 - 3.50
N, Bteroides 95 3.00 - 5.50
N, Skinneri 5 2.25 - 2.30
N; viridis v. viridis 104 2.50 - 3.00

 

 

N, X Wrightiana 97 3.75 - 4.00

 

234

Pellaea intermedia, in two samples, illustrate all scalariform

 

tracheids (x) (Figure 120).
Pellaea viridis, in two samples, illustrate all scalariform tracheids

(x) (Figure 121).

 

In order to document the ontogeny of the stele in at least one
species, and to confirm the past literature, observations of the stele
were made with N, xjglgjg, It should be noted that in the mature condi-
tion N, 3151N1§_is considered to be dictyostelic. He would expect to
find in N, 1151N1§_then, a sequence that would include the solenostelic
and then protostelic condition, as one progressed to older and older
portions of the rhizome. Indeed, this is what was observed in this
taxon. Observations made in younger portions of the rhizome, near the
basal end, clearly indicate the solenostelic condition in three different
sections (Figure 122 - 124). The protostelic condition is evident, in
older portions of the rhizome (the most basal part) and is illustrated

in Figure 125, 126).

235

Figure 120. N, intermedia. Scalariform tra-
cheid. X400. Figure 121. N, viridis.
Scalariform tracheid. X400.

 

236

 

 

 

237

Figure 122. N. viridis. Solenostelic con-
dition. X40. Figure 123. N. viridis.
Solenostelic condition. X40.

238

 

 

 

239

Figure 124. N. viridis. Solenostelic con-
dition. X40. Figure 125. N. viridis.
Protostelic condition. X40.

 

240

 

 

 

241

Figure 126. N, viridis. Protostelic condi-
tion. X100.

 

 

242

1 1,1. -1

 

 

DISCUSSION AND SUMMARY

The first formed xylem is protoxylem and has helical markings

(Figure 116, 118) at least for some species of Notholaena and Pellaea.

 

Marsh (1914) was unable to find any protoxylem in the rhizomes of
Cheilanthes (N, gracillima, N, gersica, N, Feei (as lanuginosa), N,

 

 

 

Wootonii (as Fendleri) that he examined.

Gwynne-Vaughan (1903) noted that in some ferns the protoxylem of
the stipe was continuous with that of the stem, whereas in other ferns,
the protoxylem in the stipe never connected with the stem. In the
latter case, Gwynne-Vaughan (1903) believed that the first formed
primary xylem on the periphery of the stem could be called "exarch
protoxylem" even though the cell walls were scalariformly pitted.
McCulloch 22.21: (1974) agree with that point of view and surmise
that fern rhizomes, especially those of xeric species (as investigated
here), grow very slowly and the stretchable type of protoxylem cannot
be distinguished, at least in cross section. This may have to be
modified in light of the evidence that some protoxylem has been found
and further research is conducted. Helical protoxylem cells were demon-

strated to occur in N, Galeottii and N, atropurgurea, in mature

 

rhizomes. It should be noted that these protoxylem cells were rare and
infrequent and that of the six species examined, in only two taxa were
typical protoxylem cells found. This certainly does not limit the

existence of protoxylem to N, Galeottii and N, atropquurea, nor does

 

243

244
it imply that a statement as to the universal occurrence of protoxylem

in Notholaena and Pellaea is appropriate.

 

Gwynne-Vaughan (1908) stated that the metaxylem of the Filicales
consisted of typical scalariform tracheids; the typical scalariform
tracheid possessing elongated pits arranged parallel to each other so
as to form a ladder-like pattern. He noted that the departure, in ferns,
from the tracheid type of element had been noted in only two cases:

Pteris (Pteridium) aguilina and Nephrodium (Dryopteris) filix-mas (in

 

 

the root), where true perforations occurred in the end walls of the
“tracheids" and they, therefore, had to be regarded as vessels.
Bancroft (1911) concluded that the xylem elements of the Pterido-
phytes were typically tracheids.
Bliss (1939) did a comprehensive survey on the tracheal elements
of ferns which incorporated some twenty-four genera from eight families
as classified by Eames (1936). Pellaea was one of the genera analyzed.

Bliss (1939) concluded that true vessels did exist in Pteridium latiu-

 

sculum (Desv.) Maxon and N, esculentum (Forst.) Nakai, and that the

 

water and mineral conducting elements of all other ferns investigated
were tracheids. The tracheids were, in general, scalariform, but some
Showed a tendency to serial and irregular pitting on the lateral walls.
Bierhorst (1960) conducted an extensive survey on tracheary
elements in plants. A large section of his work was devoted to the
ferns. Without going into the detailed terminologies and the ontogenic
sequences as illustrated by him, suffice it to say that he stated that
scalariform elements seemed to be of general occurrence among the higher

ferns.

245

White (1963) stated that, with two exceptions (the Ophioglossaceae

 

and Marratiaceae), scalariform lateral pitting of tracheids was recog-

 

nized as the most common type occurring in ferns and that numerous
variations of the basic scalariform pattern had been noted in the litera-
ture.

Typical fern tracheids are elongate, tapered at both
ends and have scalariform pits on all walls. In the rhi-
zome and petiole, these cells typically overlap along the '
greater proportion of their length, rather than having
relatively short oblique terminal overlaps like those of
vessel members. As a consequence, it is not usually pos-
sible to distinguish an "overlap" area between two
tracheids from the lateral walls of the tracheids.

Tracheids are traditionally considered to differ from
vessel members in at least two ways: (1) in vessel members,
there is a distinct end plate present which represents the
area of articulation between vertically contiguous cells;
no such Specialization occurs in typical tracheids; (2)
there are true perforations in the end plates of vessel
members which allow for direct and uninterrupted vertical
flow of water between cells; in tracheids the middle
lamella and primary wall constitute a barrier through which
water must pass when flowing from one tracheid to the next.

White made this interesting observation:

With the presence of vessel members in Pteridium
a uilinum and, possibly in Woodsia ilvensis, 56tfi ary habi-
tat Species, it seemed reasonable thEt this character might
be related to the xerophytic habitat. Even Marsilea in many
of its ecological niches is a functional xeropfiyte for long
periods during each year. In view of this, Species typical
of dry areas were checked, including Pellaea, Cheilanthes,
Ceterach and Notholaena, and of these, vessel-like members
were uncovered’only in the roots of Notholaena sinuata.
. . . In view of the taxonomic position of these Species,
plus the fact that other species of their genera and closely
related genera do not have tracheary elements of this
character, the presence of apparent vessel members in
Notholaena sinuata and Woodsia ilvensis points to the pos-
sible sporadic occurrence of this cell type still to be
found in other species, genera, and perhaps even in families.

 

 

 

 

 

White (1964), in summing up, stated that concerning the condition

 

of presumptive vessels in the roots of Notholaena sinuata; “This condi-
tion appears to be a random occurrence and at present I am unable to

correlate it with anything common to all species.“

245

In examining the photographs of the xylem areas, the tracheids
examined all appear to be of scalariform type, with no good criteria
for establishing and distinguishing protoxylem and metaxylem when seen
in cross section, as mentioned before.

The redundancy of the same genera being listed with several stelar
conditions in the past literature is not unusual (for example; N2_o_1_1_g_
listed under typical protostele or haplostele and reduced protostele;
Nygodium found under both typical protostele or haplostele and proto-
stele with mixed pith). Another problem f0und in the past literature
is that of not mentioning the species under a Specific stelar type.
This incomplete data presents a problem because it is known that the
members of a genus can exhibit several different stelar conditions
(McCulloch Sfiufllra 1974). One is at a loss then, to assign a particular
species wdth a specific stelar condition, if such an assignment can be
made or is even desirable to make. The past investigators themselves
are at fault for not providing sufficient information when reporting
their data. Not only are species' names missing in reports but such
important information as the growth habit, rhizome morphology, the age
or estimated age, number of sections examined and the portion of the
rhizome examined, are in most cases completely absent from the litera-
ture. Furthermore, authorities in taxonomy are not in total agreement,
and in the catalogue presented in the literature review will be found
the same taxon under different names. For example, Stenoloma chusanum
is now Sphenomeris Sh!§2£2.a"d Vandenboshia radicans has been lately
called Trichomanes radicans. Much of the older work is also defective
in that voucher specimens of the species described were not always

made for later comparisons.

247

The analysis of the stelar systems as pointed out above and in the
literature review has served to identify the taxonomic difficulties in
trying to research the genera Ngllggg.and Notholaena and to compare them
to the rhizome condition of Cheilanthes.

An analysis of the past interpretations of Notholaena, Ngllggg.and
Cheilanthes as to their stelar conditions was conducted with the results
presented in tabular ferm. Table 11 illustrates the stelar condition of
the three genera before this research on Ngllggg_and Notholaena was
initiated. The research by McCulloch Sfihél: (1974) on Cheilanthes is
included in Table 11. The occurrence of Cheilanthes Fendleri, N,
lendigera, N. microghzlla, Notholaena Marantae, N. M, N11131:;
atrogurgurea and N, rotundifolia, which are found in two or more stele
type categories, is particularly striking. The large number of
Cheilanthes species placed under typical solenostele was in large part
based on McCulloch _e_i_:__a_1_. (1974). I

Utilizing the same format as Table 11 the taxa from this research
on Ngllggg_and Notholaena can be added, and the stelar types reduced for
generalization to: solenostele, transitional and dictyostele, in Table
12. This may be the best method for a comparative study of the three
genera, even though a more complete description and analysis would be
necessary for each taxa.

It would be additionally beneficial to eliminate from the
solenostelic and dictyostelic columns any taxa that appears to be
transitional. The transitional condition describes more fully and
accurately the stelar condition found in many of the taxa.

It has been pointed out by Stevensen (personal correspondence,

June, 1976) that within the same taxon a solenostele or a dictyostele.

248
might be found. With this in mind and with the frequency of the
transitional stele in some Species the above method of description seems
the most logical in light of the present evidence. Table 13 represents
a further refinement of the rhizome conditions of the three genera with
this concept in mind.

The dictyostelic condition is seen as the exception in Cheilanthes,
Notholaena and Ngllggg, with no representatives (thus far) in Notholaena,
one in Cheilanthes, and only three in Ngllggg, The transitional stele
type is frequent in representatives of Cheilanthes, Notholaena and
2911222, The dominant Stele type, however, in all three genera is the
solenostele.

The placement of taxa previously reported that were examined in
this research, and found to be of a stele type different from previous
reports, were changed to reflect this research.

In an attempt to compare past interpretations of stelar ontogeny,
as noted in the literature review, with our research, sections of
Ngllggg.gjng1§_were made, starting with the upper portion of the young
rhizome and proceeding to the basal portion (oldest region).

The mature stelar condition of N. 111111; is a dictyostele. As one
proceeds basally then, it would be expected that the solenostelic and
then the protostelic condition would be encountered. Observations made

confirm this pattern of development in Pellaea viridis (Figure

122 - 126). The exact mode of origin of the pith and developmental

changes that occur from the protostelic to solenostelic stage are still
in question in this taxa as they are in most ferns. The Figures 122 -
126 were sent to Dr. Richard White, Department of Botany, Duke Univer-

sity, at the suggestion of Dr. Irving Knobloch, for his comments and

249
interpretations. Dr. White confirmed our opinions of the sections
(personal communication, July, 1976). The results of this investigation
confirm the past literature in that the youngest portion of the stele
was protostelic.

Esau (1965) observed that in the botanical literature the question
has often been raised as to how much of the vascular system of the stem
is foliar by origin and how much is cauline by origin.

Some workers consider that, at least in some ferns, all the vas-
cular tissue in the stem is foliar in origin (Schoute, 1! Verdoorn,
1938). Campbell (1921) believed that the stelar system of the stem was
simply an aggregate of leaf traces, implying that the stelar system of
the stem was, in fact, initially absent.

This is seemingly the case in the Marattiaceae and Ophioglossaceae

 

 

where the leaf traces are extremely large and they assemble as if to
form a central stele (Ogura, 1972).

McAlpine and White (1974) have stated that it is the sheathing leaf
bases that are most significant in the organization of the upright shoot

in the Ophioglossaceae. In this case no sharp anatomical differences

 

delimit the cells of a leaf and its sheath from the cells of the stem
during the primordial stages.

A contemporary proponent of this theory is Stevensen, as related by
White (personal correspondence, July, 1976); Stevensen's opinion also
being that the stem protostele develops from a fusion of leaf traces.

The opposing theory is one in which the stele is cauline in origin.
White (personal correspondence, July, 1976) states that:

There is considerable distance of protostele in some
young fern Sporophytes between the transition from root

250

to shoot and befbre the departure of a leaf trace. When

a leaf trace does join to the Shoot stele, it is much

smaller than the total stele in area - in other words there

is more vascular tissue than can be ascribed to the leaf

trace alone - even when only a single leaf is present in

the sporophyte . . . I think, based on my observations of

ontogenetic series and some of Wardlaw's work, that there

is a cauline vascular system independent of leaf traces

in the ferns. Hence I would see the traces going out to

leaves from the stele, and I do not believe the mature

siphonostele, etc. to be the result of merged leaf traces.

Wardlaw showed that by continual puncturing of leaf

primordia at the shoot tip, the stelar pattern became

protostelic, but that a protostele remained despite the

absence of leaf traces, etc. Therefore, a cauline system

is retained even after the loss of the foliar system.

Pellaea viridis (Figure 126) illustrates a portion of the
protostele in which no leaf traces can be observed, yet there is a
discernable amount of xylem; this observation would tend to support
White's concept as well as Lucansky and White (1976) concerning the
cauline nature of the stele. It must be stated that much more research
needs to be conducted in this area, in particular as it relates to
Leptosporangiate ferns and a comparison of them to conditions in the
Eusporangiate ferns. This research, furthermore, does not negate the
research of those who find that the stele originated by a fusion of
leaf traces.

From the literature as it relates to the ecology of the rhizome,
two points become increasingly clear. First, the growth habits as
expressed in the Cheilanthoid ferns are highly specialized and the
stelar condition is probably not genetically fixed on a rigid basis,
but is partly a response on the part of the plant to the environment
that it is in. This fact is reflected in the varying stelar conditions
and the numerous taxa occurring in a ”transitional“ category. The

unevenness of the terrain could account for the variety of

251

interpretations of stelar conditions found in the literature. For
example, a creeping habit might illustrate a solenostelic condition,
but an ascending semi-erect portion of the same rhizome might illus-
trate a transitional or dictyostelic condition. The stelar condition
as reported in the past literature most likely depended heavily on

what portion(s) of the rhizome(s) were sectioned and how many sections
were made. Because this kind of data is lacking in one-hundred percent
of the cases, a good deal of interpretation has had to take place in
analyzing the information. The following Tables 14 and 15 compare the
growth habit of the taxa (Correll, 1952; Hevly, 1963: Knobloch and
Correll, 1962; Munz, 1959; Shreve and Wiggins, 1964; Tryon, A., 1957;
Tryon, R., 1956) and their stelar condition. From Tables 14 and 15 it
can be observed that the growth habit for the most part is reflected in
the stelar condition, i.e. a slender horizontal growth habit has a
solenostele, e.g. N. 119113.: a short ascending growth habit has a
dictyostele, e.g.‘N, dealbata.

Secondly, genetically fixed characters might possibly serve for
identification and taxonomic purposes. Supporting this statement was
the observation that the taxa examined expressed a range of sclerifica-
tion patterns in the cortex and pith that seemingly might be an
appropriate diagnostic character. Tables 16 and 17 illustrate the
sclerification pattern of the cortex in the taxa and their stelar condi-
tion. These Tables (16 and 17) seem to indicate that there does not
appear to be any intergeneric or intrageneric relations between stelar
taxa that have uniform sclerification (N, neglecta, N, Newberrzi, N,
atropurpurea and N, 2!!!.)- It also appears that there are no correla-
tions between growth habit (Tables 14 and 15) and sclerification pattern
(Table 16 and 17).

252
In summary, this research has attempted to ascertain a number of
points. This research has: (1) provided detailed descriptions of the
rhizome anatomy of selected Species of eighteen members of the genus

Notholaena (seventeen species of which had not been previously described),

 

and seventeen species of the genus Pellaea (none of which have been
previously described); (2) provided a logical systematic method for
describing the rhizome anatomy in a consistent fashion by using the
terms solenostele, transitional stele and dictyostele; (3) determined
that scalariform tracheids (as examined in the macerated xylem tissue of

N, Galeottii, N, rigida, N, Standleyi, N, atropurpurea, N, intermedia

 

 

and N, viridis) are the dominant water and mineral conducting cells of
the xylem; (4) determined that in both genera there is at least one
species (N, atrgpquurea and N, Galeottii) that has helical protoxylem

 

cells; (5) documented the ontogenetic development of the stele type in
at least one species (N, viridis); (6) determined that the major stele

type in Notholaena and Pellaea is a solenostele, with some species being

 

transitional and only Pellaea exhibiting the dictyostelic condition;
(7) determined that in general the rhizome growth habit described as
horizontal to semi-erect is likely to be a solenostele or transitional
stele, and that the rhizome growth habit that is described as erect is
likely to be transitional or dictyostelic; (8) determined that the

presence of xylem parenchyma is predominant in both genera (Notholaena

 

and Pellaea) and in all stele types; this is in contrast to Cheilanthes,
where a correlation was found between the solenostelic condition and no
xylem parenchyma and the transitional and dictyostelic condition and
the presence of xylem parenchyma; (9) determined that distinctive

sclerification banding patterns are found to occur in the cortex, but

253
there is no correlation of genera and banding patterns; and
(10) determined that the rhizome anatomy will not serve aS a diagnostic

character to effectively separate Cheilanthes, Notholaena and Pellaea,

 

at least at the present.

Further research in the following areas would be beneficial in
elucidating anatomical problems in the Cheilanthoid ferns and furthering
the quest for diagnostic characters that might be used to illustrate the
complex relationships that seem to exist in this group of ferns:

(1) more species of the genera Cheilanthes, Notholaena and Pellaea need

 

to have their rhizome anatomy described; (2) experiments involving the
ontogeny of the stele should be done on a large number of taxa: (3) more
species need to be analyzed for the presence of protoxylem in the
rhizome; (4) taxa need to be examined for the possible occurrence of
vessels in both rhizome and roots; and (5) further standardization of

stelar terminology needs to be accomplished.

254

 

 

 

 

 

TABLE 11. Stele types as reported in the previous literature.
GENUS
‘ CHEIEANIHES NOTHOLAENA REEUEA
LIJ
d N. gersica
.11-
<40
as
Eu
8
..J
E?“ C. Feei N. ferruginea (aurea) P. andromaedifolia
+- C. Fenaleri N. Warantae F. atropurpurea
g8 C. gracillima N. sinuata 15'. cordata
215 N. lendigera N. tricliomanoides N. rotundifolia
SS
..1 C. Feei N. ferruginea (aurea) P. andromaedifolia
g C. Fenaleri N. Marantae 17. atro ur urea
3 C. racillima N. sinuata N. rotunaiiolia
.1: C. Eauli’ussii N. tricfiomanoides
g %.1anosa
. lenai era
"" g C. Parr i
N. visciaa
d I.”
—1 C. lendi era
EE N. micropfiWla
g
I-IJ
.—l
C
U)
3 N. microphflla
..“3
(I)
O
E
..l
O
m
m C. aemula
d C. angustifolia
'5; C. Brandegii
g C. castanea
3 N, Clevelandii
O . Coo erae
m N. Covillei

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 11 (cont'd.)

255

 

GENUS

 

‘ CHETEINIFE§

 

WK

PELEIEHC

 

 

IC L
SOLENOSTELE

Ifiddnfldflwdfinddmn

 

 

 

Eatonii
Fendleri
rac

orr u a
ntertexta
lendi era

n e 1
xicana
crop y In
r10 h 11a
not 0 aeno des

 

$5

1

 

%

 

3

3

 

*fi

 

rin 1ei’
tomentosa
ooton

t

F

El

fl.
3-

 

Marantae

sinuata

 

 

N,
P.
N.

atrqpurpurea

 

feTCata
rotuna1f011a

 

 

 

256

TABLE 12. Stele types in previous literature reduced to basic
conditions (solenostele, transitional, dictyostele).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GENUS
”cumming NOTHOL_A_§NA PELLAEA
C. aemula N. Aschenborniana P. allosuroides
N, angusfifolia NP aurea (ferruginea) N, andromaedifolia
. Brandegii . brach us . atropurpurea
Ci castanea FL canaiga v. candida F, Breweri
C, Clevelandii N, candida v. Copelandii F, Eria esii
N; Coo erae EL cocfiisensis Fl ?a1cata
C. Covfillei N. Galeottii F, intermedia
C, Eatonii N, Gra i F, longimucronata
Lu C, FenHleri N, [emmonii N, ovata
.4 C, gracillima NR Narantae F, rotundifolia
‘“ t. horriduWa N. —l'““ne ecta F. Skinneri
:3 N. intertexta N. New err i N. X Nrigfitiana
u; C. lendi era N. r a
‘J C, Linafieimeri N, §c%a??neri
C. mexicana N. sfnuata
C, micropfiilla ND §tanalezi
C, rio h lla
3.3 C. noffioiaenoides
: N. Prlnglei'
“1 CL tomentosa
d N. Wootonii
5 N. Nrigfitii
_J C. Feei N, aurea (ferruginea) P. andromaedifolia
g C. Penaleri N. intergerrima P'. atropurpurea
53 C, racillima N, limitanea v. mexicana N, brachyptera
C, au uss N, Narantae N, mucronata v.
gg'C, lanosa N, parvi?olia cali?ornica
C, lendi era N, sinuata P. notabilis
N. arrx _. tricfiomanoides _. rotunaihlia
£9 Feei N, aurea (ferruginea) P. andromaedifolia
C. Penaleri N, Marantae N, atropurpurea
N; gracillima N, sinuata F, cordata
to C. lendi era N. triangularis F, HeaIBata
>- N. persica _. trTcTIomanoides N. teroiaes
:3 N, rotunai?olia
D N. viridis

 

 

 

 

257

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W

 

 

 

TABLE 13. Refined stele types.
1
GENUS
m m PEIINEI
C. aemula N. Aschenborniana P. allosuroides
N. angmstifolia N. aurea N. andromaedifialia
. Brandegii . Eracfi us . atropurpurea
C. castanea N. canaifia v. candida N. Nreweri
C. Clevelandii N. canaiaa v. Copelandii N. Eria esii
C. Coo erae N. cocfiisensis N. i’a'lcata
m C. Covfillei N. Naleottii N. intermedia
E C. aton N. ra N. longimucronata
m C. fiorriaula N. emonii N. ovata
2 C. intertexta N. neglecta N. SEinneri
... C. Lindheimeri N. Newberr i N. Y Nrigfitiana
C. mexicana N. ri 13a
N. micropfiylla N. s nuata
. rfo h lla N. Stan-d'lezi
C. noffiofiaenoides "
N. PringleT
E ' C. tomentosa
:3 C. Wootonii
3 N. Nrigfitll
E
C. Feei N. intergerrima P. brachyptera
i C. Penaleri N. leitanea v. mexicana N. mucronata v.
C. racillima N. Narantae ca ornica
C. Eaulfissii N. parvi?o'|ia P. notabilis
m C. Tanosa N. trichomanoides N. rotundi?olia
2 C. lenai era
N. arr!
N. persica P. dealbata
N. ero es
N. v r s

 

 

 

258
TABLE 14. Notholaena rhizome habit and stele type.

 

 

 

 

 

 

 

 

 

 

Species Habit Stele
N, Aschenborniana stout, short creeping solenostele
N, gggg§_ thick, short creeping solenostele
N, brachypus short, thick, erect solenostele
N, Egggjgg_v. candida short creeping, branched solenostele
N, Egggigg v. Copelandii short, compact solenostele
N, cochisensis short, thick solenostele
N, Galeottii short creeping solenostele
N, N531; short creeping solenostele
N, integerrima short, thick transitional
N, Lemmonii short, thick ascending solenostele
N, limitanea v. mexicana horizontal transitional
N, neglecta horizontal, short creeping solenostele
N, Newbergyi horizontal solenostele
N, parvifolia compact, short creeping transitional
N, IIQINN. horizontal, slender solenostele
N, Schaffneri short ascending solenostele
N, sinuata short, thick, horizontal solenostele

 

N, Standleyi short, horizontal solenostele

 

259

 

 

 

 

 

 

 

 

 

 

TABLE 15. Pellaea rhizome habit and stele type.
Species Habit ' Stele

__ allosuroides stout, short creeping solenostele

N, andromaedifolia slender, cord-like solenostele

N, atropurpurea stout, compact solenostele

E, brachyptera moderately stout, transitional
elongate

__ NggNggi compact, massive, solenostele
ascendent

__ Bridgesii short creeping solenostele

E, dealbata short ascending dictyostele

N, falcata short creeping to erect solenostele

N, intermedia elongate, slender wolenostele

N, longimucronata moderately stout, solenostele
elongate

N, mucronata v. californica erect transitional

E, notabilis moderately stout, transitional
compact

N, 93233_ slender, creeping or solenostele
compact

N, pteroides transitional

N, Skinneri short, stout solenostele

N, viridis erect dictyostele

 

 

260

 

 

 

 

 

 

 

 

 

 

TABLE l6. Notholaena: stele type and sclerification pattern.
Species Stele Sclerification
N, Aschenborniana solenostele none-heavy
N, ggggg solenostele light-heavy-light
N, brachypus solenostele heavy-light
N, Egggigg v. ggNgigg_ solenostele heavy-light
N, gggg1g2_v. Copelandii solenostele heavy-light
N, cochisensis solenostele heavy-light
N, Galeottii solenostele heavy-light
N, N:gx1_ solenostele heavy-light
N, integerrima transitional heavy—light
N, Lemmonii solenostele heavy-light-heavy
N, limitanea v. mexicana transitional heavy-light
N, neglecta solenostele uniform
N, Newberryi solenostele uniform
N, parvifolia transitional heavy-light
N_‘[191gg. solenostele heavy-light
N, Schaffneri solenostele light-heavy-light
N, sinuata solenostele heavy-light
N, Standlexi solenostele heavy-light-heavy

 

261

 

 

 

 

 

 

 

 

 

 

TABLE l7. Ng]_l_a_e_a_: stele type and sclerification pattern.
Species Stele Sclerification
N. allosuroides solenostele light-heavy
N. andromaedifolia solenostele light-heavy-light
N. atropurpurea solenostele uniform
N. brachyptera transitional heavy-light-heavy
N. W solenostele heavy-light
N. Bridgesii solenostele heavy-light
N. dealbata dictyostele heavy-light
N. _f_a_l__c_a_i_:_a_ solenostele light-heavy-light
N. intermedia solenostele light-heavy
N. longimucronata solenostele heavy-light
N. mucronata v. californica transitional heavy-light
N. notabilis transitional heavy-light
N. 9_v_a_i_:_a_ solenostele uniform
N. pteroides transitional heavy-light
N. Skinneri solenostele uniform
N. viridis dictyostele heavy-light

 

 

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