GRASS FAMILY 99 



divaricate; lowest flower of the spikelet sterile, like the empty glumes; lemma of 

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

 tain sides: Colo. — X.M. Submont. — Subalp. Au. 



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

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

 involute, pilose; spike 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.— X.D.— S.D. Submont. Jf^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, awned, strongly divaricate, 2-3 cm. long; lowest floret usually ster- 

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

 Wash. — Mont. — -X.M. — -Ariz. Subalp. — Alp. Jt^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 U])permost 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. — Wvo. — 

 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 glvmies subulate-setaceous, some of the lower usually bifid, divergent, 

 5-6 cm. long; lemma 10-11 mm. long, 3-fid, 3-awned. Hillsides: Mont. — Wj'o. 

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



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

 cm. long, 1-2 mm. 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: W^ash. — -Ida. Svibmont. Je. 



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



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

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

 Empty glumes 2, inserted more or less obliquely, rigid, a'\\'n-]ike, subulate or 

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

 roimded on the back, usually awned. Palet shorter than the glume, 2-keeled. 

 Stvles very short, distinct; stigmas plumose. 



Lemma long-awned. 



Spike broad; spikelets spreading. 



Emptj 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. rirpinicus. 

 Plant slender; spike long-exserted ; lemma scabrous-hispidulous. 



2. E. jejunus. 

 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. direr.figlumis. 

 Empty glumes l.">-30 mm. long. 



Lemma hirsute or villous. 3. E. canadensis. 



Lemma hispidulous-scabrous to glabrous. 



Robust; spike usually included at the base; leaf-blades 8-1.5 mm. 



wide. 5. E. rohuslus. 



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

 wide. 6. E. brachyslachys. 



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



7. E. sirialus. 

 Spike narrow; spikelets erect, appressed. 

 Lemma pubescent. 



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



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



