2918] The Grasses of Illinois 315 



P. spliacrocarpoii and has larger leaves. The plants arc light green 



in color. 



ILLINOIS specimens: Without locality, Frenc7t in 1905. jackson co. Grand 

 Tower, Gleason, Jiilv, 1902. peoria co. Peoria, Brendel. union co. Cobdeu, 

 Earle in 1886. 



Panicum sphaerocarpon Ell. 

 (Fig. 84) 



Hitchcock and Chase '10, 251. 



Vernal form with culms 8 to 20 inches tall, seldom erect, the tuft 

 usually spreading, not pubescent except on the nodes ; sheaths almost 

 as long as the internodes, slightly ciliate on the margin, otherwise 

 smooth ; ligules too small to lie distinguished -, 

 blades 2 to 4 inches long, 7 to 14 mm. wide, 

 rough but not pubescent on the upper surface 

 except along the margin near base, smooth 

 below ; panicles about as Avide as long ; spike- 

 lets short pubescent, 1.6 to 1.8 mm. long, al- 



„. DO o^ o -1 most spherical. Autumnal form spreading on 

 Figs. 83-84. — Spike- ^ • 



lets: 83, P. polyanthes; the ground, branching from the lov/er and 



84, p. sphaerocarpon middle nodes ; blades and panicles not greatly 



reduced. 



This species is usually found in sandy soil. It is not common in 



Illinois. The plants are usually light green with purplish spikelets. 



CHRISTIAN CO. Taylorville, Andrews, Aug., 1898. jackson co. Without lo- 

 cality, French, June, 1878, and May, 1905. 



OLIGOSANTHIA 



The species belonging to this group are as a rule stout, erect plants 

 vdth stiff leaves and large spikelets. The sheaths are usually hairy, the 

 ligules never more than 1 mm. long and the spikelets 3 to 4 mm. long. 

 In the autumnal form the culms branch near the top. 



Panicum leibergii (Vasey) Scribn. 

 (Figs. 85 and 86) 



Hitchcock and Chase '10, 289. 



Vernal form with erect, slender culms in small tufts; culms 1 to 

 3 feet tall, usually pubescent ; sheaths shorter than the internodes, con- 

 spicuously papillose-pubescent, the hairs spreading ; ligules not visible ; 

 blades 2 to 6 inches long, 7 to 15 mm. wide, short, appressed papillose- 



