432 Ulmace^. 



ELM FAMILY. UL.MACE.?:. 



Trees and shmbs with tough wood and of about one hundred and forty species grouped 



in tlurteen genera and widely distributed througliout the teni[""rate regions of the north"rn 



heniisplieie. Five genera are represented in tlie United States, and three of these by trees 



of tie' east''rn and snuthern states. TIu'V are i harae-terizfd as folli:)\vs : 



Lravcs deciduous, simple, pietolate. alternate, in two ranks, serrate, pinnately veined, 

 unequ,al al base, conduplic-.ate in llii' bud and with usually fugacious stipules; buds with 

 several scales, FIoiii r.s small, perfect, inoneeiious or polygamous, clustered, or the pistillate 

 solitary; calyx regular. 4-'.)-parted cr lobed ; petals none: stamens as many as the lobes of the 

 calyx and opposite them, ^^■itll str.aight exserted liliments and introrse 2-cened anthers opening 

 longitudinally; o\'ary l-cel]ed witli solitary, anatropous or amphitropous ovule suspended 

 from apex of the cell: styles two. Fruit a saniera, drupe or nut; seed with little or do 

 albumen, straight or curved embryo, and usually Hat cotyledons, 



KKY TO THE GEXKKA. 



a Fruit a samara: flowers iierfed and usuall,\" expanding before the h*aves,,.. Ulmus. 



a- Friiil papilhise nntdike ; llowers iiolyganious, expanding with the h'aves Planera. 



a^ P'nut LI i!rup(.' ; flowers on the nrw growth of the season Celtis. 



THE ELMS, Genus ULAIUS L. 



Trees or rarel.\' shrubs with scaly ridged bark. hea\".\" tou^li \\'OoiI and somewhat zigzag 

 bramhlets. and of about cighlei-n species, of wdiiih six or sevrn arc fnund in eastern United 

 Stati>s and four of these in the niuiheasteru states. None are found in tlie Pacific states. 



Lr/iri s ineejuilateral, straight-\'eined and simpdy or dr)idd,\' seri'ate ; stipailes searioiis 

 caducous; buds with several clo.sely imbiirntcd scales in 2 r.aiiks. Floircra from axillary 

 buds on twigs of the previous season's ginwtli ami usually expanding bid'ore tlie leaves (or in 

 autiunn from the axils of the leaws nl' tlie season), mostly perfect and in fascicles or 

 rac'cmes, with bibracteolate iicdicids ; cal,\"x campjanulate, membranaceous jiersistent with 

 4-'J imliricatt^d Ir.lics : stamens ."-li, cxserlcd with slender filaments and oblong anthers; ovary 

 sessile nr stalked, cuniiircssnl willi 2 dixcrgent styles stigmatic on inner fai cs, Ucelled and 

 containing a singli:- arnphil ropous (i\-ule. Fruit a flat orbiiailar or oblong menibranaceoiis 

 1-seeded samara \\'iuged all around (or cxcepding apexi, subtended b.\" the withered calyx 

 and sometimes tiiipied with the I'emnants of the styles ; seed ceimpressed with straight embryo 

 and no :tlbumen. 



t liinifs is the ancient Latin name of (he Elm. 



KFY TO THE SPEriES. 



a Lea\'es smooth or nearl.A" so al.iove and s;imara with \\'iiig-like ciliale margin 

 b -Vs Ijroad as sei-d portion 



Samai-a with glabrous sides: buds glalimus and bluntl\' pointed.. U. Americana. 



Samara hairy ou siiles ; buds acuminate and ijubei ulcus U. raceniosa. 



h- Narrower than seed iiortion : liranchlets corky winged: samara narrow, stipitate and 



hirsute XT. alata. 



a" Lea\es \-er.\' rough abo\'e ; samara not ciliate : buds rust,\"-tomentose. . , , TJ. pubescens. 



Fnr ,s;i, cicx ,viv iiir ISJ-Fsn. 



THE PLANER TREE, Genus PLAXER.A Gmelin. 



A genus of a single sjiecies ef small Irees nf soulhcasteru United States and the lower 



.Mississi])iii \-alle.\'. resianbliiig tlie 1-diiis. The characters are gi\en in the descriiition of species. 



It is named after Juliii Jacoh I'ltiiici-. a (.Jcrman I'nd'cssor of Bolany of the eighteenth 



century. 



For .ijicrirs s-rr pji. 19ll-l'Jl. 



THE HACKBERRIES. Gents GKLTIS T.. 



Trees and shrubs id' lil'l,\- nr sixl,\ s|ieiies, widely disiribiiied throughout ihe temperate 

 and tropical regions. Four species are foinul in Xnrlli .Vnii'vica, two Ixdng shrubs of the 

 southern stales and soiilhward and Ihe oili.-i' Iwn i;ee< .'iiiiild lo ciuwider.'ii ion here. 



I.i<lrrs poMite.l. ire(||idaleral |iil'lialel\ -\-eiiied or sonielinies :',-,''iweined al Ivise: si'llllles 



"■eicbraiioiis. caducous. I'lmrrrx polyga iiio-inono'cions. small, api-earing wilh the unfolding 

 of till' le.'iM's or soon afler on I lie br:!iii'ldeis ot Ihe \ear. pedicellale; Ihe staminate in 



a c cles iieiir Ihe base of llie spool ami Me iiispll-il,, Milil:r\ or few loi;etliel' from Ihe axils 



