32 Flora of the Palouse Region 



52. SITANION. 



Cespitose perennials, with spike-like panicles, which readily 

 break up into segments: spikelets 2-3 at each joint of the rachis, 

 rarely solitary, 1-5-flowered: empty glumes 2 to each spikelet, 

 subulate and entire, or lanceolate and bifid, or parted into several 

 long-awned lobes: flowering glumes lanceolate and acute, or those 

 of the lowest floret sterile and subulate, entire with a single awn, 

 or trifid and three-awned. This genus is hardly distinct from 

 Elymus. 



Empty glumes many-lobed: central awn of flowering glume 5-10 cm. long: 



lowest flower sterile. S. villosum. 



Empty glumes entire, subulate: lowest flower perfect. S. leckenbyi. 

 Empty glumes entire, lanceolate or lobed, awned: lowest flower perfect. 

 Spike flexuous: flowering glume smooth or nearly so. 



S. FLEXUOSUM. 

 Spike stout, erect: flowering glume pubescent. S. brodiei. 



S. villosum J- G. Smith. Culms stout, mostly erect, 20-30 cm. high: leaf 

 blades short, flat, strigose-pubescent and somewhat hirsute, 4-8 cm. wide, 

 sheaths densely hirsute: spike 6-8 cm. long, the base enclosed in the elon- 

 gated upper leaf-sheath: empty glumes 3-8- parted, each lobe bearing a slen- 

 der awn 3-8 cm. long: lowest floret sterile, its glume resembling the empty 

 glumes: flowering glume of perfect florets lanceolate, 3-awned, the middle 

 awn stout, 8-10 cm. long, the lateral ones slender and usually shorter. Com- 

 mon in dry ground. 



S. leckenbyi Piper. Culms stout, erect, 60-80 cm. tall: leaf-blades stiff, 

 erect or ascending, 4-12 cm. long, involute, glabrous beneath, strigose above, 

 sharply acuminate; sheaths glabrous, or, on sterile shoots, ciliate: spike 10- 

 15 cm. long, slender, usually erect, long-exserted: empty glumes 4, equal, 

 entire, setaceous, 2.5-3 cm - long: flowering glume lanceolate, 8-9 mm. long, 

 smooth at base, scabrid above, bifid at apex and tipped with a straight awn, 

 3-4 cm. long. Bars of Snake River at Wawawai. 



S. flexUOSUm Piper. Culms tufted, .5-1 m. tall, erect: leaf-blades 4-12 

 cm. long, involute, strigose-pubescent on both sides, or the upper nearly 

 glabrous; sheaths glabrous or on sterile shoots villous: spikes slender, erect, 

 flexuous, 8 cm. long, long-exserted: empty glumes subulate-setaceous, 3-4 

 mm. long, tipped with an awn 9-10 mm. long, sometimes with two very 

 short lateral awns in addition: flowering glume lanceolate; smooth at the 

 base, scabrid above, bifid, bearing a divergent awn 3.5-4 cm. long. Bars of 

 .Snake River at Wawawai. 



S. brodiei Piper. Culms erect, 40-50 cm. high: leaf-blade stiff, smooth 

 on each side, involute 9-14 cm. long: spike pale-green, long exserted, erect, 

 5-7 cm. long: empty glumes subulate, entire, 7 mm. long, bearing an awn 

 10 mm. long: flowering glume lanceolate, densely appressed pubescent, 10 

 mm. long, rarely with two short lateral awns in addition: joints of the rachis 

 linear, flattened, scabrous on the margins. Bishop's Bar, Snake River. 



