GRASS FAMILY 99 



(Uvarioate; lowest flower of the si)ikelet sterile, like the empty glumes; lemma of 

 the seeond flower about 1 em. long, trifid or entire; awn 5-7 cm. long. Moun- 

 tain sides: Colo. — N.M. Sub)nont. — Subalp. Au. 



10. S. strigosum J. G. Smith. Stem 3-6 dm. high, glabrous or minutely 

 pubescent above; leaf-blades 1-2.5 dm. long, 3-6 mm. wide, flat, or the lower 

 involute, pilose; sjiike stout, exserted, 8-12 cm. long; empty glumes entire or 

 bifid, subulate-setaceous, 5-6 cm. long; lemma 8-10 mm. long, 3-cleft above, 

 the middle awn 5-7 cm. long, the lateral ones 1-2 mm. long. Valleys: Wash. — ■ 

 Ore. — -N.D. — -S.D. Submont. Je-Au. 



11. S. rigidum J. G. Smith. Stem 1-2 dm. high, glabrous; leaf-blades 

 3-8 cm. long, 2-3 mm. wide, rigid, involute, scabrous above; spike 2-8 cm. long, 

 exserted or included at the base; empty glumes 4, entire or two of them divided 

 to the base, awncd, strongly divaricate, 2-3 cm. long; lowest floret usually ster- 

 ile; lemma 7-9 mm. long, trifid; awn stoat, divaricate. Mountains: Calif. — • 

 Wash. — Mont. — N.M. — Ariz. Subalp.— Alp. Je-Au. 



12. S. glabrum J. G. Smith. Stem 3-6 dm. high, smooth and shining; 

 leaf-blades 7-15 cm. long, 2-5 mm. wide, flat, becoming involute; spike 5-8 cm. 

 long, sub-flexuose, the base usually enclosed in the uppermost sheath; empty 

 glumes bifid to near the base, the lobes subulate-setaceous, 6-8 cm. long; 

 lemma 7-8 mm. long, entire or minutely bifid. Hills: Calif. — Wash. — Wyo. — ■ 

 Utah. Subalp.— Alp. My-Au. 



13. S. montanum J. G. Smith. Stem 2-4 dm. high, glabrous below, scab- 

 rous above; leaf-blades 5-10 cm. long, 3-4 mm. wide; spike erect, 5-10 cm. long; 

 empty glumes subulate-setaceous, some of the lower usually bifid, divergent, 

 5-6 cm. long; lemma 10-11 mm. long, 3-fid, 3-awned. Hillsides: Mont. — Wy i. 

 — Utah — Ore. Submonl. — Mont. Je-Au. 



14. S. basalticola Piper. Stem 1-3 dm. high, smooth; leaf-blades 3-10 

 cm. k>ng, 1-2 nun. wide, minutely scabrous on the nerves above; spike erect, 

 3-5 cm. long, barely exserted; empty glumes subulate, or some cleft to near the 

 base, spreading, 3-4 cm. long; lemma 8-10 mm. long, glabrous, glaucous, 3-fid; 

 middle awn 3-3.5 cm. long, divergent, scabrous, the lateral ones about 1 mm. 

 long. Basaltic soil and sandy slopes: Wash. — Ida. Sub?nont. Je. 



77. ELYMUS L. Lyme-grass, Wild Rye, Rye-grass, Buffalo Rye. 



Perennials, with rootstocks and cylindric spikes. Spikelets sessile, usually 

 2 or 3 at each node, but in some species mostly single, 2-several-flowered. 

 Empty glumes 2, inserted more or less obliquely, rigid, awn-like, subulate or 

 lance-linear, persistent, awn-pointed or awned. Lemma oblong or lanceolate, 

 rounded on the back, usually awned. Palet shorter than the glume, 2-keel(!d. 

 Styles very short, distinct; stigmas plumose. 



Lemma long-awned. 



Spike broad; spikelets spreading. 



Empt.v glumes lanceolate to lanceolate-subulate: spike dense. 



Empty glumes lanceolate, 5-7-nerved, thick and strongly curved at the base; 

 spike erect. 

 Plant robust; spike scarcely exserted; lemma glabrous or nearly so. 



1. E. virQinicus. 

 Plant slender; spike long-exserted ; lemma scabrous-hispid ulous. 



2. E. jejuntis. 

 Empty glumes narrowly linear-lanceolate, neither conspicuously thickened 



nor curved at the base; spike often nodding. 

 Empty glumes usually minute, less than 15 mm. long. 4. E. diversiglumis. 

 Empty glumes 1.5-30 mm. long. 



Lemma hirsute or villous. 3. E. canadensis. 



Lemma hispidulous-scabrous to glabrous. 



Robust; spike usually included at the base; leaf-blades 8-15 mm. 



wide. 5. E. rnhustus. 



Slender; spike long-exserted; leaf-blades seldom more than 5 mm. 

 wide. 6. E. brachi/stachys. 



Empty glumes setaceous, hirsute; lemma hirsute; spike laxer. 



7. E. siriatus. 

 Spike narrow; spikelets erect, appressed. 

 Lemma pubescent. 



Empty glumes lanceolate, 5-nerved. 8. E. vulpinus. 



Empty glumes lance-subulate, indistinctly veined. 9. E. anguatus. 



