147 



Pinaceae 



Jiinipevus virginiana L. Hanover area, frequent on the rocky 

 exposed bluffs and from them invading the perched dunes. 



Grainineac 



Andropogon scoparius Michx. One of the most typical sand 

 grasses in the Hanover, Amboy, Dixon, Oquawka, and Havana areas ; 

 very frequent in the bunch-grass association and persisting from it as 

 a relic in the Panicuni pscudopuhesccns and the black oak associations. 



Andropogon furcatiis Muhl. An abundant and important grass, 

 but by no means as common as the preceding species. Hanover, 

 Amboy, Dixon, Oquawka, and Havana areas, normally in the bunch- 

 grass association, but persisting as a relic in the black oak and 

 Solidago associations, and sometimes appearing on blowout deposits. 



Sorghastniiii nutans (L.) Nash. Hanover, Amboy, Oquawka, and 

 Havana areas, in the bunch-grass association, and as a relic in the 

 edge of the black oak association. 



Digitaria fiUforniis (L. ) Koeler. Hanover, Oquawka, and Ha- 

 vana areas, apparently not native, but coming in as a weed along 

 roadsides or in too closely cropped pastures. 



Leptoloma cognatum (Schultes) Chase. Abundant in each area 

 except Winnebago and Kankakee, chiefly in the bunch-grass, where 

 it may be dominant, also as a relic in the edge of the black oak 

 association, in the Panicuni pscudopuhesccns association, and on the 

 windward slope of blowouts ; it also appears early on blowout de- 

 posits. 



Paspaluin sctaccuni Michx. Hanover, Dixon, Oquawka, and 

 Havana areas, typically in the blowsand association, and continuing 

 on the deposits, also as an interstititial in the bunch-grass and in bare 

 spots at the edge of the black oak association. 



Ponicum pscudopuhesccns Nash. Abundant in each of the five 

 areas in a variety of situations ; common in the bunch-grass asso- 

 ciation but usually as a secondary species; characteristic of the 

 association to which it gives its name; persisting as a relic in the 

 blowout succession in the windward slope and deposit associations; 

 frequent in open sunny places in the black oak forest ; rare in the 

 blowsand association ; and, in the Dixon area, depauperate plants per- 

 sist in the mats of Polytrichum. 



Panicuni virgainm L. Common throughout but not abundant, 

 usually in the bunch-grass association, but in the Hanover area one 

 of the commonest dune-formers on the blowout deposits or the crest 



