Flora of the Palousc Region ■ 33 



53. EIvYMUS. 



Perennial cespitose grasses with spike-like inflorescences which 

 do not readily break up into segments: spikelets 1 7-flowered, 2-4 

 at each joint of the rachis or rarely solitary: empty glumes entire, 

 about equal, two to each spikelet: flowering glumes acute, acum- 

 inate or awned, entire. 



Glumes long-awned. 



Spike narrow, erect: spikelets appressed. E. GLAUCUS. 



vSpike broad, usually nodding: spikelets divergent. E, canadensis. 

 Glumes not awned or only short-awned. 



Culms very stout, 1-2 m. tall, densely tufted. E. condensatus. 



Culms about 1 m. tall, not so stout and not tufted. E. triticoides. 



E. glaucus Buckl. Culms .5-1 m. tall, erect: leaf-blades spreading or 

 drooping, 10-30 cm. long, 6-16 mm. wide: spike-like panicle narrow, erect or 

 rarely nodding above, 5-15 cm. long, greenish or purplish, glaucescent: 

 spikelets usually appressed, mostly in pairs, 3-6-flowered: flowering glume 

 rough near the apex, tipped with an awn nearl)' twice as long. Common 

 and variable; some forms approach E. canadensis. 



E. canadensis L. Culms stout, about 1 m. tall, pale and somewhat 

 glaucous throughout: leaf-blades flat or involute, nearly smooth: spike pale- 

 green, flexuous or nodding, 10-15 cm. long: spikelets 3-5-flowered, mostly in 

 pairs, somewhat divergent: flowering glume hairy, the stout awn usually 

 spreading. Infrequent on the bars of Snake River. 



E. COndensatUS Presl. Culms 1-2 m. tall, stout, densely tufted: leaf 

 blades flat, glaucous, smooth except the scabrous margin, usually 1-2 cm. 

 broad: spikes 3-30 cm. long, erect: spikelets 3-6-flowered, usually several 

 at each node, commonly densely crowded: flowering glumes mucronate point- 

 ed. Abundant in moist soil. 



E. triticoides Nutt. Culms erect, about 1 m. tall, not densely tufted: 

 leaves 4-6 mm. wide, sometimes scabrous: panicle spike-like or with some of 

 the lower branches elongated, usually purplish, rather loose: flowering 

 glume acuminately short-awneil. Moist banks of Snake River. 



Family 13. CYPKRACKAE. 



Grass-like or rush-like herbs: stems slender, solid (rarely hol- 

 low), triangular, quadrangular, terete or flattened: leaves narrow 

 with closed sheaths: flowers perfect or imperfect in spikelets, one 

 (rarely two) in the axil of each scale (glume or bract): spikelets 

 solitary or clustered, 1 to many-flowered; scales two-ranked or in 

 a spiral, persistent or deciduous: perianth hypogynous, of bristles, 

 or interior scales rarely calyx-like or wanting: stamens 1-3, rarely 

 more: ovary i-celled, sessile or stipitate; ovule 1; style 2-3-cleft: 

 fruit an akene; endosperm mealy; embryo minute. 



