102 FOACEAE 



2 mm. long or less. E. virginicus submuticus Hook. River banks: Man. Ills. 

 Kans. 'Wash. Plain Submont. Jl-Au. 



17. E. Howellii Scribn. & Merrill. Somewhat tufted perennial; stem 6-8 

 dm. high, glabrous; leaf-blades spreading, flat, 10-15 cm. long, 4-8 mm. wide, 

 minutely scabrous; spike exserted, 7-10 cm. long; spikelets usually in pairs, 

 2-4-flowered; lemma 1012 mm. long, acuminate, usually awn-pointed, sparingly 

 scabrous toward the apex. E. glaucus breviaristatus Davy. Grassy ground: 

 Alaska Ore. Jl-Au. 



18. E. condensatus Presl. Stems tufted, 1-2 m. high, stout, striate, 

 scabrous or scabro-puberulent above; leaf-blades 3-10 dm. long, 5-10 mm. wide, 

 more or less scabrous; spike 2-4 dm. long; lemma 12-15 mm. long, acuminate 

 or awn-pointed. Hills and alkaline ground: Alta. -Neb. -N.M. 'Calif. -B.C. 

 Plain Mont. Je-Au. 



19. E. triticoides Buckley. Stem slender, 6-8 dm. high; leaf-blades 1.5-3 

 dm. long, about 7 mm. wide, flat or somewhat involute, scabrous on the margins 

 and nerves; spike about 1.5 dm. long, erect; spikelets 12-18 mm. long, 4-6- 

 flowered; lemma 8-10 mm. long, 9-nerved, glabrous, awn-pointed. Meadows, 

 hillsides, and bottom lands: Alta. -N.M. Calif. Wash. Son. Mont. Je- 

 Au. 



20. E. ambiguus Vasey & Scribn. Tufted perennial; stem 6-10 dm. 

 high, glabrous; leaf -blades 1-4 dm. long, 2-4 mm. wide, rigid, flat or at last in- 

 volute, scabrous, especially above; spikes 7-12 cm. long, erect; spikelets 5-9- 

 flowered, 12-18 mm. long; empty glumes about 12 mm. long, scabrous; lemma 

 10-12 mm. long, obscurely 5-nerved; awn 3 mm. or less long. Canons and 

 hillsides: Colo. -Utah. Submont. Mont. Je-Au. 



21. E. strigosus Rydb. A cespitose perennial; stem 5-7 dm. high; leaf- 

 blades 1-2 dm. long, about 3 mm. wide, flat or involute, scabrous; spike 1-1.5 

 dm. long; empty glumes linear-subulate, 7-9 mm. long, very scabrous; lemma 

 lanceolate, about 1 cm. long, awn-pointed or short-aw r ned. Foot-hills and shale- 

 slopes: Colo. -Wyo. Submont. Je-Jl. 



22. E. salinus M. E. Jones. Tufted perennial; stem 3-6 dm. high, smooth; 

 leaf-sheaths enlarged, long-remaining and becoming fibrous; leaf-blades thick, 

 involute, puberulent near the throat, the basal ones 1-1.5 dm. long; stem-leaves 

 5-10 cm. long; spike 5-10 cm. long, narrow; spikelets about 12 mm. long, 7-9- 

 flowered; empty glumes 4 mm. long, somewhat falcate; lemma about 8 mm. long. 

 Saline soil: Utah Wyo. Son.- Submont. Jl. 



24. E. simplex Scribn. & Williams. Stems tufted, 3-4 dm. high; leaf- 

 blades 4-10 cm. long, 3-6 mm. wide, becoming involute, strigose-scabrous above; 

 spikes 6-^10 cm. long; rachis flattened and scabrous on the edges; spikelets singly 

 or sometimes in pairs, about 1.5 cm. long, 5-7-flowered; empty glumes very rigid, 

 unequal, 8-10 mm. long; lemma about 7 mm. long, smooth, acuminate; awn 

 4-6 mm. long. Alkaline soil: Wyo. N.M. Ore. Submont. Subalp. Je-Jl. 



24. E. villiflorus Rydb. Stem 4-6 dm. high, finely retrorse-pubescent; 

 leaf -blades 1-2 dm. long, about 2 mm. wide, strongly involute, scabrous above; 

 spike 1-1.5 dm. long; spikelets 1 or 2 at each node; lemma lanceolate, 5-nerved, 

 villous-hirsute, about 1 cm. long. Plains and foot-hills: Colo. Alta. Plain 

 Submont. Jl. 



25. E. arenicola Scribn. & Smith. Stem 8-15 dm. high, glabrous; leaf- 

 blades 2-4 mm. wide, 2-3 dm. long, strongly involute; spike slender, 1.5-2.5 dm. 

 long; spikelets in pairs or singly, about 6-flowered; lemma acute, mucronate or 

 awn-pointed, about 10 mm. long. E. dasytachys litoralis Am. auth., not Griseb. 

 Sand dunes: Wash. -Ida. Ore. Son. Je-N. 



26. E. cinereus Scribn. & Merr. Stem densely short-pubescent, except 

 where protected by the sheaths, about 1 m. high; leaf-blades 2-3 dm. long, 5 mm. 

 wide, often involute; spike about 15 cm. long; spikelets usually 2 at each node, 

 3-4-flowered; lemma 9-10 mm. long, strigose. Dry plains: Calif. -Nev. Ida. 

 Son. Je. 



