ge quit a= (iil |, Moor IM | DISTINGUISHING MARKS OF OUR NATIVE ELAS IN THEIR WINTER CONDITON Thesis for the Degree of 5. S. lu Seymour L. Ingersen £2 SS yey CD wr? eS SENIOR TEESIS On DISTINGUISHING wannsS Of Our NATIVE BLS tin Their WINTER CONDITION. a. r' \» S. Li*Ingerson, hichican Agricultural Collere, 1829. THESIS NISTIVMATTSHIMS MARS Of Our MATITVE WIS Ty T.eLY wETTes SOrmMLEtroy. _— S. L. Invercen. This study of the eli:s was -ntiertaken for the pirpose of determin- ing; (1) the characteristics which distinzuish the elms from our other t>ees,-- and (2) the characteristics peculirr ty the indivitu.l specie. The former annpears quite easy, for any wooldsman is able to recornize an eli without Tiffiaultry. ilovever, 1t tent not be so ecsy for hin to tell hov he knevv an eln fron avy other tree, or, in other woris, whet Aistinguishins cosractoristics the elms possess. It wrroul? be stil. 7 i: cs easy for him to name the individual “eteristics of the differ- 4 4° ~ ent svecles of elms, thourh he could pick ou 16 trees at a silence. The elms belong to the order URTICACVAT, the nettle familv. MYO neme of the venus to which they belong is Ulius. The three elms in -r ® e a a? ~ 4 aw tee: aq .fS *. e “7 os ~~ @ VY. +8 ‘wy 7 - . x. y. - “"= 2 wlCuigays are.-- U Liu s LULV Et, sl LOA. 9 biict rod Cai, OF Seay yO Ga mo IT j—~ ius Americona, L., hnovn by various names 7s, Americen elit, white eln, rray elm, soft eln, svramp elm anid water elw;-- and Ulsus race.z979, Thome, the cork ell or rot” e@1n, t Ine of the veneral characteristics of the elms is the ‘vide, sormeni7- ing form of the tops. This, novwever, is izost noticeable in the Anmer- ican and red els. It way be opterver to some extent in the older teeesg of rock ein, Lut the younger speelscens shovy a rether compact, conical form. In the American and ret elins the side bLranches are com- + N ” my . ‘ -$ - 9 “"y .9 + oo ae > “y' ms oo 7) paratively fev, riviary ths voint teoes 2 rather unevreretrical appewrsnen. This procably accounts for the fact that comprrative.: fev of these 100229 trees are planted for share or ornanent. As they rrovw older they talc of g more rraceful anvearance, an’ their wide, sprendins tovs make then Saonge the most beautiful of our trees. Another and a very stronely marked choracteristic of the elms is the arranvement of the leaf scars on the tyvics sni of the side brancicc olone the main stems. The srranzement of the brenches of course fol- lovs that of the leaves of the previous season, since thev are devel- oved from bite in the axils of tre lenves. The arrenzenent is alter- nate and tro-rantvesd. Tt is eepecisllivy neticeable in rapidliv srov7ins, worient stems. when the stems are ccich inclined fro. a vertical posi- tion tiuis arrancgeweit is not so adnarent. In such eases the tentens of the twigs is to turn uvvard, end thus they ali aeprear to start rox “a near the uprer side of the branche. Tne tvo ranks of buds from “nich the twigs grow sre in fact less than one helf the cirecurference of the branth anairt. The puds on one site are slisntly to the right of the center of the leat seurs and thrse on the other side to the left. See nlrtes I. and Il. Tt is thus a shorter distance vetvreen the ranks of buds one ~ravy around the branches than it is the other wav, and thus the buds all s:-en to turn toveard one Side which, for want of a better term, tay be enlled the face side. In the lateral bronches this frce side is tho nover side; in the wp- richt shoots I have found nothing to deterimine on which side it will be. In plate I., figures 1, 3, 4, 6, and 7 si.o7 the face site and fifures 2 end & the ovposite side. The bud scales of the elms are arranged in tv) ranks wiakine a cross eeetion of a bud somewhat oval. "nis is shovm in siate ITI., Siowre 2, mich 18 a corss section of a leaf or branch bu. The ten“ency in all the elyws is to prowtuce more flover tuts an the snort, side twigs than on the sentral shoot. Thoece thet are foun? on (2) tne central shoots are usuativ alone the middle portion of the yearly erovth, the buds at the base ani ti: beine leaf bits. In the side twies the arrangement is the same, but the flovrrer buds mar often be found almost to the base and the ti» of the tric. ™e Inst bud is usually, iv not alraevs, a leaf but. The leaf buts and fiover puis are easily distingzuisnei vey their snape, the leaf waa being much more slender. Relov the strony well-teveloved bucs are ususily found one or more sicaoli Intent buts. See nlates I. and TI. The inst bud on each tvic appears at first to be a tersinal bu-, . ; 4 but slocer examination shovs it + we lA dad ohn 2 ist ow ‘2 be avi Ti anmer ee The real terminel bud dies at the end of the season and drops off, leaving a very small scar. The Location of this scar is shovn at (a), in plate I., fimuire &. The lenticels a,yvear at first as minute dots, being in fact verv aA siail masses of cork just underneath the enidernmi in. ney rrahvalily enlarge and finaily break throush the eviierzis. They cre circular in outline, but, craing to the cracking of the Lark, eupear more or lene alaneratada alany thea ator, Ae thar Aayvelon thar braome more prominent and gradually change in shave from oblone to circular, and finally, bv the swelling of the bsrk, become elonrated nceross the steii. ™he len- ticels are usually more numerous just below the leaf scazs. In distinctuishing the crecies of elms the ~eneral shone and apnear- ance of the trees are first to be notice. The red elm usua@iiv has put few larrve branches which form a rather loose, «neynzwetrical ton. Tne pranehes very often start fron. the trunk at long intervals. rhere they leave the trun tre form with it a rather small cngele, but usualiv they gredually curve dovnvord till, in lont branch?2s, the tivs shov a Jeciied droo». THe American elm hrs usually the most snrendine hrbit. The to»n is often larze, svirretrical, and urn-shianet, esvecially in Lsolated eneciiiens in the fields. The rock elm has a larver munber _ —— —ad (4) of branches anti is of a less svrendine hebit then the other tro. The masses of cork on its vranches also serve to distinmiish it. Tne vpveasreance of tne twires 1s aiso of use 1! determanins the species. Those of the red elm are quite thick, "ith large noves, the internodes isaking a slight ancle vith exch other. They are Licht nw wray, sovered iv a white dovn which hes a decidedly bluish cypeaance, more notizeesile on the face side. my -_ oD twizrs of the Americsn elm sre sSlen’er, the internotes, esrecially the younzer ones, somevhat spool- cnaped. All the younzver nodes sre of about the same size. See plate I., firures i and 2. The twvirs are brovnish in color, often covererA by ga downy rroarwth in the older vortions. ™n the rocn elm the sizall srenenes ore corky, often very minh so, Gee olote TT™. mhe vounrer tries not covered by cork are usuaily slenter, eacr internote melting 2 Aecidet angle with the precedinc. see plinte I., firures 3, 4 and fF. They are grayish in color and cre eovered by a fine, ~hnite down. Some ditferences way olso be noticed in the lenticels of the three species. Thoce of the red elm are nt first very licnt in color, but later assuise a sligntly yeilx»7 color. They are mith lsrzver than thos af the ather elms thoneh nat nearly eq myrerane, Gee nicete TT., Fire ure 8, In the American elm the lenticels are livht in color snd small. They are quite nunerous excent on the very youn> tvigs. On a fev of these IT have veen unabl» to find then. See plate II., fisure l. In the rock elm they are of a yeliovic) color, rather smaller than in the American elm, usuaily of about the same nucber. On some of the emall- est twisrs thev are very smali, and in some cases none could be found. The buds of the different svecies shov marked cifferences. Those of tne red eim are very lorze, 4 - 10 rar, long, and often nenrly as Lroal as lonr, blunt, pubescent, Lrowmn except for a plue blooi like that seen on the tris. The buds, inelutine the latent bucc, sre sormernet more munerous: in the red elm than in the other svecles. Qe ” o 1 rr oe amar ge. 7 oe ~ ” * ony - ™~ ° o “~ 47 . . “-aey ct le 7 7 ae tt 1 = “v 4 pbAve Liles bagure os. Inu the Awersacan GCiu the wudas are GaaguveyY LLae- tened, pointed, 2 - G6 mn. long, brown, smooth or nesorly so, shinins see plate II.. ficure l. The buais of the rock elm etanid out vell from the interno“es. They are 2- 8in.. iom7, end pointer. Tneir color is a readjisn brown. Tnev are smooth ot the tin, but dovny below ex- cevt on the edres of the ecales. See plate II., fimire °. erecent few voints of Aaitferenze which vould be of use in distinsulsning between the apeqies, Those of the red eli are perhans a little shorter and more oval in snave. Tn the but-coale sears, ton, there is little to distinguis® the = a species. In all, the bud-seale scars extend about one-half ver around the triers, sometizces considerably more than nalf vay, so that they overls), a% shoyn in piste I., fimure 7, (bd). In the read els: thev are sornervhnat larcer, and the lover ones often appesr micn like folis of the bark. The leaf-—scars precent s:arked iilfferences in the three svecies, ani sare a valuacle means of Aeterrination., Tn the red elim thev are large, vroad, often clliot-.cal, or sometimes slightly reniform in shnpe. Tney have . convex surface with a rim ground the eare. They sre of e@ eray color, somevthet lichter than the porrk. See plate II., fisure 2. Those of the American elm are very broed, sometimes slivhtiv renifor:, sometimes ellipticsl or obvlong-elliptical, cuite orominent and convex. Their color is brownisn, nearly the cae 9s that of the bark. gee ‘plate Iil., figure l. In the rock elu they are more or less cori.ate in sneave and not so prominent as in the American elm. In color +e nore cray, muicn lighter than tie bork. Sve plate II., figure @. These are amons the marked cheracteristics which serve to distin- cuish the elms. These cheracteristics should moke the Aeterzination (6) of the sveciecs of elms comparctively ersy. ft is hovee thet this study may have shorn not onlv the differences existing betreen these vortic-— ular trces, but also that eve:. the esuson,lace things avout us are vell worthy of our carefil stuiy. —-- -—-— - Plate I. Llm Twigs. X 7. figures / and 2; lwigs of American elm: &, leaf buds, 8, flower buds, ¢, latent bude, @, bud-scale scars. Figures 3 V and J,’ Lwigs of rock elm: a, leaf buds , 4 flower buds; ¢ Jatent buds, d, bud-scale scars. figures Gand 7; Lwigs of wed elm: 2 Sscaros terminal bud; 6, bud-scale scars; c, leay buds; A flower buds. Plate I. Llm Twigs. x =. kig. /, Americanelm , Fig. 2, rock elm. fig. J, red eloe. a, leaf buds; & flowerbuds ; ¢ latent buds; gd leat Scars, @ dud-seale scars, f, lenteceds. Plave II. fig. J, Cross section of a leaf bud. «2, the central Shoot. , leaves. fig. 2, A leay more highly magnified. hig 36, Cross sections of rock elm twigs, Showing cork. Fig. , The same more highly magai fred. fig. $-/0, Portions af rock elm branches. KOCAL USE ONLY,