30 GKAMINEAE 



2. S. purpurea (Walt.) Kuntze. Sand-grass. A tufted annual, 

 about 1° hiffh : leaves short, sparingly ciliate : panicle .]'-2' lon<i;. — In 

 sand in the Missouri Kiver bottom at Courtney. Conunon in one 

 locality. Also occurs at Qnindaro, Kansas. .Tuly-September. 



38. DIPLACHNE F.eauv. 

 Spikelets several-flowered, sessile on the rachis, forming slender 

 spikes. Two lower glumes empty, keeled, acute, unequal. Flowering 

 glumes longer, 1-3-nerved, 2-toothed and mucrouate between the teeth. 



Spikelets 2^ '-4^^ long. 1. D. fa.icicniaris. 



Spikelets 5'^-6'Mong. 2. I), acuminnia. 



1. D. fascicularis (Lam.) Beauv. A decumbent or ascending annual, 

 l°-3° high : spikes pauicled, partly enclosed in upper sheath : spikelets 

 3//_5// long, 5-11-flowered. — Often common on muddy shores in low 

 grounds. June-October. 



2. D. acuminata Nash. Kesembles the last, but spikelets longer, 



the flowering scales acuminate, entire (obtuse and two-toothed in D. 



famcuhiris). — Often common on mud-flats, especially at Courtney. 



June-September. 



39. ERAGROSTIS Meauv. 



Spikelets paniculate, 2-many-flowered, flattened. Two lower glumes 

 empty, short and keeled, l-nerved. Flowering glumes keeled, 3-nerved, 

 not pilose at base. Palet 2-nerved, persistent on the rachis after the rest 

 of the flower has fallen. 



Culms creeping and rooting. 1. Iii/pnnidis 



X^ulms ascending or erect. 



Spikelets large and flat, forming a narrow crowded 



panicle. 2. E. major. 



Panicle open, its branches capillar^'. 

 Culms lo° high or less. 

 Spikelets .^-many-flowered. 

 Spikelets 2-r)-flowered. 

 Culms much-l)ranclied. 

 Culms sparingly branched. 

 Culms 10° or more high. 



Spikelets yellowish, usually 3-5flowered. 

 Spikelets purplish, usually G-lO-flowered. 



1. E. hypn^ides (Lam.) B.S P. Annual, forming large patches 

 leaves short, G^^-18" long : flowering branches 2'-.")' high : spikelets 

 dioecious, 10-30-flowered, 2'^-8'^ long, clustered.— Common along 

 streams, especially along the Missouri Kiver. June-October. 



2. E. major Host. 6'-2^° high : leaves flat, sharp-pointed, V-6^ 

 long: panicle 2'-6Mong, l^^-2^^ wide: spikelets lance-oblong, Z'^-Q'' 

 long, \Y^ wide, usually 8-2()-flowered. — Common in waste places. 

 July-October. 



3. E. Purshii Sclirad. Densely-tufted and mueh hranching, 3'-18'' 

 high : Iftiives about 2' long: panicle from I'-IO' long, its branches loose 



