780 GRAMINEJE sitanion 



tapering into an awn as long or longer than the body : flowering glumes 

 4-7 lines long, nearly smooth to hirsute, bearing a slender scabrous awn, 

 1-2 inches long. On river banks and bars, Oregon to Nova Scotia, Georgia 

 and Texas . 



E. Caput-Medus2E L. Sp. 84. Stems slender 12-20 inches long, genic- 

 ulate below: sheaths about equalling the internodes: ligules very short: 

 leaves 2-3 inches long, involute: spike stout, 13^-2inches long, dense : spike- 

 lets 1-2-flowered : empty glumes narrow, rough, spreading, about an inch 

 long : flowering glumes hispid, 3-4 lines long, gradually tapering into an 

 awn 2-2% inches long. On dry prairies, southwestern Oregon : introduced 

 from Europe. 



55 SITANION Raf. 



Tall annual or perennial grasses with usually flat leaves and 

 terminal spikes. Spikelets 1- to several-flowered, sessile, usually in 

 pairs in alternate notches of the pointed rachis. Empty glumes 

 forming an apparent involucre to the cluster: glumes very long, 

 often 2-parted to the base, the divisions unequal, 2-cleft and 

 long-awned: flowering glumes long-awned, 2-toothed or 3-awned. 

 Palets a little shorter than the glumes, 2-keeled. Stamens 3. 

 Styles very short, distinct, with plumose stigmas. Grain sparsely 

 hairy at the summit, adherent to the palet. 



S. elymoides Raf. Journ. Phys. lxxxix, 103. Elymus Sitanion Shultes. 

 Stems simple smooth, 6-24 inches high : sheaths smooth to rough or hirsute, 

 usually shorter than the internodes, the upper ones often inflated and 

 enclosing the base of the spike: ligules short: leaves 2-7 inches long, %-2 

 lines wide, usually scabrous, sometimes hirsute, flat or involute; spike 2-6 

 inches long : spikelets 1-5-flowered : empty glumes entire or divided, often 

 to the base, the divisions subulate and bearing long unequal slender awns : 

 flowering glumes 3-5 lines long, 5-nerved, scabrous toward the apex, bear- 

 ing a long slender divergent awn 1-3 inches long. In dry soil, California to 

 Brit. Columbia and Kansas. 



S. glaber J. G. Smith. Stems stout, erect, densely cespitose, 12-20 

 inches high : sheaths loose, longer than the internodes, glabrous : leaves 

 2-6 inches long, glabrous beneath : spikes 2-4 inches long, barely exserted : 

 awns of the flowering glumes 2-2^ inches long. Washington to California. 



S. villosum J. G. Smith. Stems stout, mostly erect, 10-15 inches high: 

 sheaths densely hirsute: leaves short, flat, strigose-pubescent and some- 

 what hirsute: spike 3-4 inches long, enclosed in the upper sheath: empty 

 glumes 3-8-parted, each part bearing a slender awn 2-4 inches long; flow- 

 ering glume lanceolate, 3-awned, the middle awn stout, 4-5 inches long, 

 the lateral ones slender and usually shorter. Common in dry ground 

 about Pullman, Washington. 



S. Leckenbyi Piper Fl. Palouse Reg. 32. Stems stout, erect, 2>£-3 

 feet high : sheaths glabrous or on sterile shoots ciliate : leaves stiff", erect, 

 2-7 inches long, involute glabrous beneath, strigose above, sharply acu- 

 minate : spike 5-7 inches long, slender,usually erect, long-exserted : empty 

 glumes 4, equal, 2)^-3 lines long, entire, setaceous: flowering glumes lan- 

 ceolate, 5-6 lines long, smooth, at base, scabrous above, bifid at the apex 

 and tipped with a straight awn 1^-2 inches long. Bars of Snake river at 

 Wawawai, Washington. 



S. flexuosum Piper 1. c. Stems tufted 1)^-3 feet high, erect: sheaths 

 glabrous or on sterile shoots villous : leaves 2-6 inches long, involute, 

 strigose-pubescent on both sides, or the upper nearly smooth : spike slender, 

 erect, 4 inches long, long-exserted: empty glumes subulate-setaceous, 1-2 



