ae eT-4

Fea)
ee

eS

Pi
<

ae

al 1s
eee

eee
THE WINTER ¢

cs
a

egree of .

ee
ria, me

rae
ied

Pa
Ps
=

Bt ay

ds
C59

Senior Agricultural Thesis.

"The Winter Condition of Cur Violets"

By Bertha Raker,
a

Class ‘98,

Michicsan Agrioultural College.
THESIS
The Winter Condition of Cur Violets.

ups Rew «2 «<2» a  - —e  < -

 

 

 

Many people huve written ahout the violet,its oultiva-
tion und its vulue,but as vet,no oomvarison has heen mide of
tre rootstoaxs ot tne different sveales of our aomnon violets.

In tne spring or Summer some of them dear fPlowers,each
of wnieh seems to svring from the surfuce of tne eround wile
others nroduce brancnes Prom u few inches to u foot or more
in lensth. On these branches we have the flowers ,euch with
its Separate Stulk. All are Suvvlied with an abundance of
green leaves throughout tre growing season. After the vlants
have produced flowers and seeds,and even while producing these,
in muny cases the leaves are asSimilating materials for the for-
mation of starch and vrotoplasSm; some of which is Stored away
in short rootstocks ready for the use of the plant on the ap-
proach of the following spring. Late in autumn,or winter,
these leaves perish,and those which oame from the rootstock
nave Scars ut the thiokened buse. The vDlants also perfeot dure
ing the summer,rudimentary leaves and flower buds which are
ready tO grow and bloSSoOm aS soon uS the ground becomes warm
in the sprine.

It is the purpose of this thesis to illustrate ,describe

and compare the rootstocks of some of our violets as seen in

the winter or early spring.

Tre plants were grown in the botanic garden,and were dug

93823
(2)

up wausned and curefully examined. All the noints of Likeness
as well as of difference were curefully noticed.

Violets are divided into two sectinrs: Caulescent ,trhose
wnien munifestly huve stems and Acuulescent ,t»os¢ which apnear
to be siemless or nearly so.

A prominent botunist suys,"a rootstock is a eeneral nume

for any horizontal or oblique perennial stem which lies on the

Ground or is buried beneutn its Surfice. It sends off fibrous

roots of u slender sort whenever it rests on,or is aovered bv

tne soil,und usually nroduces from its anex some kind of aerial
stem,eitrner leafy or as a flower stulk,ywhich rises into the air
and light." Trev ynuive well murked nodes und internodes,the for-
mer veuring leaves reduced to saunles. Tne avex advanres and
at lenet® rises into an ordinury stem,vrile the onvosite and oléd-
er purt grudually dies uway.

A vud forms in the axil of each scule-like leaf. Ronts pro-
ceeaq from Or neur tre nodes. The thickened roststocks ure
eorged with tre nourishing mutter Pormed in the leuves and stored
there for the use of the plant. These roristocks answer the
Sune Durpose as do tne thickened leuves of other vlantS,-as a
sort of Store-nouse where the vlent mar place tre food accumula-
ted in excess.

In the first specimen, Viola Palmata,L.e,or the common blue
Violet,the rontstock is verv short,brirnging tre brunches close

2

tovetner. The buses wrere the leaves hive fallen off are very
(3)
thick. Tney are adout 1-2 ar. and have a sort of three lobed
apDeurance ,as thougy they had been vinched. In Plate l,the
drayving Shows these thickened bases ant also the manner in
wiish the new growth Starts from the nodes. (a) sows the
Staron granules,which are very small and angular in appearance.
(c) another view of the new growth; (d) the older portion of
the rootstock. The rontstock is 13 mui-in diameter. The
leaves of this svecimen are roundish ,cordate or reniform,how-
ever,there wus a sreat variation. This is the most common of
our violets,and grows in moist,or drvyish,und especially stee-
ile ground.

The rootstoocks of Viola cucullata,Grav.,is very much length-
ened so that the branches are not crowded so closely together
aS were those of the Viola palmata. They are arransed at in-
tervals,two fiftrs of the circumference of the sStalk,forming
what is oalled the five ranked arrangement. The bases from
which the leaves have fallen are verv thick and fleshy. (See
illustrations (bd) and (c),¥igure I). The new growth starts
from these nodes. The rootS come out near them or at their
corners. This syrecimen is 1? mn. in diameter. The staroh
granules are small and verv irregulur in Shape.

Viola Canadensis ,bL-,or the Canadian violet ,was the third
Soecimen examined. The rootstock was very lone and slender,
bveine about 7 mm. in diameter. Ir this resvnect it Somewhat ree
sembles the vrevious specimen,except it does not have as many

Scales. From the buses of the stemS,uni where the branches
(4)
have been broken off,the fioro-vussular bundlcsS may be Seen as
in Fig. III,(a).

The buses of the leaves are SO thickened us to form deep
notches in the stock,us is shown in (b),Fig. III. The roots
are wery numerousS,uni very much divided. In this snecimen was
found an abundance of Stach,in large granules,(a). Above the
ground this snvecimen has long branahyine stems. The leuves ure
heart-Shaved,vointed serrate. This vlant grows in rich woodSe

Viola Rostrata,Prush.,or the ong spurred violet. The
rootstock creens along under ground,branching and sending ud
new plants from these nodes. It is 4mm in diameter. The stocks
are not fleshy and no not have as muny scales aS do the speci-
mens previously mentioned. It has very long,fibrous roots.
Ahove ground the plunt sends uv very tall branching ,jointed
stems. ‘The starch wus very scarse,only a few graniles were
found. These were sharply anpular und ratner irregular.

Viola Sagittata,Ait.,the Arrow-leaved violet. In this
the new growth forms a crown. The rootstock is two(°?) om high
and 1-3 in diameter. The new branches are ahout 13.m. in
leneth and 5 oom in diameter. The roots of t»is snecimen were
larger and more fleshy than those of any other svecimen examin-
ed,except 59lea concolor ,wnich is not u true violet. The Starch
in this species was abundant. The granuleS are not as large us
Viola Canadensis,and are irregular in Shane. The leaves are
Smooth or hairy and vary in form from oblong heurt-Shuped,or

halbred-shaned,to oblon? lanceolate ,or ovate.
(5)

Viola oanina,L. Tris is the smallest svecimen examined.
Tne rootstock wus verv slender,m°asuring only 3 mm in diameter.
It is snort and as many branches. There are tiny leaves com-
ing out at intervals along the stem. The leuves are heart-Shav-
edgand are not vointed,excent those which grow near tne tov of
tre plunt. There was no starch found in this species,in which
respect it resembles the Viola blunda. This species srows in
damp Or Shadv places.

Viola pubescens,Ait., The rootstock is lone and tavering,
measuring 5 mm at its greatest diameter. There are many Scars
where the brancres nave been. The roots are not numerous ,being
verv few in number as comvared with any other specimen. The
new growth,branches from the nodes along the side of the stock.
The leaves are verv bdroadly heurt-sShaned,toothed and somewhat
DoOinted. The Starch was auite abundant , the Pranules resembling
those of the Viola sagittata. This is the yellow violet whish
grows in the woods.

Viola pedatu,Le The rootstock resembles thut of the Viola
Sugittata in the manner in which the new growth Starts from the
stock. It has many scales like the sagittata. The stock is
very woody and on examination of a transverse section,large cells
were found wnich vere mostly hexagonal in section,with verv thin
walls. The drawing,Fig. VIII,(o0),shows these cells and their
contents. The starch was very scarce,the granules being mich
Smaller than any *ound in the vrevious svecimens.e The leaves

differ from those of any other violet. Thev ure three or five
(6)
divided or pvarted,lineur or narrowly spatulate. This is what
gives the variety tne name of Birdfoot violet.

Solea concolor,Ginea. This is called the green violet and
differs from all the other violets examined. The rootstock is
verv longs and twisted,huvine 1 Somewhat gnarled unpeuranceé.

The stock is hard and woody. Tre lLleuves difter entirely from
anv of tne other violets. They ure oblong,vointed at both ends,
and are entire. They are of a light green color. Thre stems
grow uv to a heient of 60 cm.oOr more. It has Small inconsvi-
GUNNS flowers. There was no starch found. A transverse section
waS made and examined. The cellsS were very large and vurving

in Shane. The sestion showed some hexazonal,ventaszonal ,and
even Square cells. This vlant grows in damn vlaces in the woods
and iS rather rure.

Viola blanda,Willd. The rootstock is slender,heing 4 mm
in diameter. It differs from all the rest in the Large number
of verv longs fibrous roots. These roots were 12 om. in length.
The leaves were very small and roundish heurt-Shapned in outline.
A transverse section Showed 26118 ‘hich were irregulur und of
vastly differing sizes and Shanes. ‘here were no starch cells.
It is usually found in damp pluces and und-r tamarack trees.

Tne vrincinal differances found were the lack of Starch in
some svecimens and the abundance in which it was found in others.
There wus also a great variation in the arveurance,the sizes and
Shape of the rootstocks. Some were exceedingly snort and thick

woile otners were lone and slender.
 

     

as !
ty Sf
f {
f i.
HA iF
ij Rg
5 ‘ fi
Uy
SG,
b- (j
’ r P
t “ wn se
a yr
a ea
a re
‘

j — v2
yi AE Da A a
. » , u \
ay - of _
= py] A ees i=

i q
 
 
ROOM USE ONLY

Fet 699

 
- - my tnt aha

tO ests

 

 
  

MICHIGAN STATE UNIVERSITY LIBRARIES

iii) iii

5748