312 Bulletin No. 205 [March, 



lower surface short appressed pubescent; spikelets 1.6 to 1.7 mm. 

 long, densely pubescent. Autumnal form usually spreading, the culms 

 much branched at the nodes, forming tufts of leaves, often bending 

 the plant to the ground ; leaves much reduced and concealing the very 

 small panicles. 



This species is usually found in moist places. In general appear- 

 ance it is much like P. Jiuaclmcae and its subspecies, but in P. tejines- 

 seense the upper surface of the leaves is not pubescent. Hitchcock and 

 Chase cite some intergrading specimens in which a few hairs occur on 

 the upper, blade surface. The plants often have a purplish tinge. 



CHRISTIAN CO. Taylorville, Andrews, June, 1899. lake co. Zion City, Hill, 

 Aug., 1905; Waukegan, Gates, June, 1908; Beach, TJrnbach, July, 1909. rock 

 ISLAND CO. Banks of Mississippi near Eock Island, McDonald, Sept., 1900. 



Panicum villosissimum Nash 

 (Fig. 80) 



Hitchcock and Chase '10, 233. 



Culms in large tufts 10 to 20 inches tall, rather slender ; culms and 

 sheaths very densely long pubescent, giving them a soft, fuzzy appear- 

 ance; nodes bearded; sheaths shorter than the internodes; ligule 4 

 to 5 mm. long; blades 2 to 4 inches long, 5 to 10 mm. wide, densely soft, 

 appressed pubescent on both surfaces ; spikelets 2.2 to 2.3 mm. long, the 

 pubescence spreading. Autumnal form usually much branched, espe- 

 cially at the lower nodes, the leaves closely appressed to the stem, the 

 plants often prostrate; blades not much reduced, usually with a few 

 long hairs on the upper surface. 



This species is found in dry, usually sandy soil, in open woods or 

 on hillsides. The vernal form is light olive green ; the autumnal form 

 is often tinged with purple. 



LA SALLE CO. Starved Rock, A. Chase 1606. madison co. Without locality, 

 Eggert 293. 



COLUMBIANA 



The species of Columbiana differ mainlj^ from those of Languinosa 

 in the absence of long, spreading hairs on culms and sheaths, the 

 pubescence being short and appressed. The ligule is short, usually 

 not over 1 mm. long. The blades are firm and always less than 1 cm. 

 wide, rarely with long hairs on the upper surface. The autumnal form 

 is freely branched. The spikelets are always covered with short 

 pubescence. 



Panicum tsugetorum Nash 

 (Fig. 81) 



Hitchcock and Chase '10, 245. 



Vernal culms 12 to 18 inches tall, usually ascending but often bent 

 over near the base ; densely pubescent with very fine, soft hairs, closely 



