nil 



*Alli()ni(t II l/<-t(Ul! 11(11 * Aiiiliiui.'<iii ps'iltisUK'/n/K 



Adciiioiic ciiIiikI ricK ll'ii- rac'i ii m Ioik/i pi I ii ii, 



* LcxqiU'iU'Jhi s/iKthiiliit/i *h'ii/iiiiti ijl iitiiioK,! 



*CriKl(it('ll(i Jdiiifxi'i *('liriiKopx'ix ciiiiipiirina 



*Po]ilii!si(i grart'iilciis S(ir,(l(i,p) tiiis.snii r/t n.six 



Baptixiil hrili-lcdld IJi-lidiit/iilx scdhrrrii)! ilx 



• Ailiiirphd i-diH'xci'iix ( 'di'i'upxix pdliiidtd 



This group in the prairie formation is obscnred by the 

 presence of (55 species, or 56 percent, of eastern distribution, 

 to be regarded as derivatives of the Athmtic flora 1 element: and 

 the remaining 18 species, or 15 peirent, include 1) of transcon- 

 tinental distribution. 4 introduced species. 2 [* Aristhhi fiihcr- 

 ciilosd and '''Sp(iriili()/ds c/'i/jjfin/iij'iis) with a range along the 

 coast of the Atlantic and (ireat Lakes and locally in the interior, 

 and 8 whose range is local or unknow n. namely. '■'■ I'm/icdji/ sii.. 

 Vlilo.r h/p'dd. and Aiifi'iiiidrid sp. 



The importance of the Sonoran element can be shown to 

 lietter advantage by excluding all these species which occur 

 commonly in otlier associations in the state, limiting the list to 

 the plants most characteristic of the sand region. Of the 28 

 species thus selected, 1 is local, 2 range along the coast and the 

 Great Lakes, ti are eastern or southeastern, and lU. or (')8 per- 

 cent, are western or southwestern. In the preceding list and 

 in the paragraph following it. 22 of these species are marked 

 with an asterisk. The (5 eastern species included are 



Pd II ii'U III rttcjiiilt II III I'lil ijipiii II III liiiiii- 



Ciipcrilx til I rill III 'ix MliildI'dd pinicldld 



Sdli.r ti'ixtix Iniidctix 1 1 nil I'l ifiili iix 



The (5() species of the sand region which are found only in 

 the black-jack as.sociation include 1 of local distribution, lldi- 

 ludlnis iUiiiDi'iisis: 1 introduced species. ('Iidiiirhlnn ririi/is; ',) of 

 western distribution; and "i5 of eastern and southeastern range, 

 indicating plainly the eastern relationships of the flora, and 

 the floral similarity of the black-jack to the other forests of 

 central Illinois. < )f these 55, all but one. Fo/i/(/o>nnii cristdtiiiii. 

 occur also in other plant associations within the state, while of 



