GRASS FAMILY 101 



attenuate above; awn 3-4 cm. long. River valleys: 111. Mo. X.M. Mont. 

 -Ida. Plain Submont. Je-Au. 



6. E. brachystachys Scribn. & Ball. Stem 3-10 dm. high, smooth; leaf- 

 blades 1-2 dm. long, 6-10 mm. wide, semi-involute, smooth or somewhat scab- 

 rous beneath, finely scabrous above; spike dense, nodding, 8-15 cm. long; spike- 

 lets usually in 2's, 3-5-flowered ; lemma 11-13 mm. long; awn scabrous, 2-4 cm. 

 long. Prairies and plains: Mich. Tex. N.M. (Black Hills) S.D.; Mex. 

 Plain Submont. Je-Au. 



7. E. striatus Willd. Stem 3-9 dm. high; leaf-blades 1-2 dm. long, 4-10 

 mm. wide, smooth or slightly scabrous beneath, pubescent above; spike exserted, 

 nodding, 6-12 cm. long; spikelets divergent, 1-3-flowered; lemma about 6 mm. 

 long, hispid; awn 1.5-3 cm. long. Woods and river banks: Me. X.C. Tex.- 

 X.D. Plain Submont. Je-Au. 



8. 'E. vulpinus Rydb. Stem 5-7 dm. high, striate, erect; leaves 1-1.5 dm. 

 long, 2-6 mm. wide, scabrous on the margins; spike exserted, 1-1.5 dm. long, 

 6-7 mm. thick, slightly nodding; spikelets 1-2 at each node, 4-6-flowered; lemma 

 linear-lanceolate, 8 mm. long; awn 8-10 mm. long. Meadows: Alta. Xeb. 

 Plain. Jl-Au. 



9. E. angustus Trin. Stem 4-10 dm. high, striate, smooth; leaf -blades 

 rigid, 7-15 cm. long, 3-6 mm. wide, smooth beneath, scabrous above, with in- 

 volute margins; spike rather slender, its base enclosed* in the upper sheath; 

 spikelets in pairs, 2-3-flowered, erect-appressed ; lemma lanceolate, acuminate, 

 8-10 mm. long; awn scabrous, 4-6 mm. long. Banks: Wyo. Ida.; Asia. Sub- 

 mont. Je. 



10. E. glaucus Buckley. Stem 6-10 dm. high, smooth; leaf -blades flat, 

 scabrous on both sides, 6-15 mm. wide, 5-20 cm. long; spike erect, 6-15 cm. long, 

 5-8 mm. thick; spikelets in pairs, rarely in threes or single, 3-4-flowered; lemma 

 scabrous towards the apex, 5-nerved, 7-10 mm. long, with a white margin, or 

 in var. lenuis Vasey [E. americanus Vasey & Scribn.] narrower and with purplish 

 margin; awn scabrous, 7-15 mm. long. Among bushes and in meadows: Mich. 



X.M. Calif. B.C. Submont. Subalp. Je-Au. 



11. E. marginalia Rydb. Stem 6-10 dm. high, glabrous or pubescent at 

 the nodes; leaf-blades 1-2 dm. long, 7-10 mm. wide, flat, scabrous beneath, 

 usually pilose above; spike 1.5-2 dm. long; spikelets usually in pairs, 4-5-flowered; 

 lemma 10-12 mm. long, glabrous and shining; awns 8-20 mm. long. Lake shores 

 and banks: B.C. Wash. Submont. Mont. Je-Jl. 



12. E. nitidus Vasey. Stem 7-10 dm. high, stout and leafy; leaf-blades 

 1.5-2 dm. long; spike about 1 dm. long, ^rect; spikelets 1-2 at each node, 3-5- 

 flowered; lemma about 1 cm. long, obscurely 5-nerved, smooth or nearly so, 

 shining; awn scabrous, of about the same length. Mountains: Ore. Wyo. 

 B.C. Submont. Mont. Jl-Au. 



13. E. Petersonii Rydb. Stem 6-8 dm. high, slender, glabrous; leaf-blades 

 flaccid, 1-1.5 dm. long, 4-5 mm. wide, light green, minutely scabrous on both 

 sides, or sparingly pilose above; spikelets in pairs or single; lemma about 1 cm. 

 long; awn about 1 cm. long. Mountains: B.C. (Selkirk Mts.) Mont. An. 



14. E. Saundersii Vasey. Stem 6-10 dm. high, smooth; leaf -blades 12-20 

 cm. long, becoming involute, finely scabrous; spike 12-18 cm. long, somewhat 

 nodding; spikelets usually in pairs, 2-4-flowered; lemma lanceolate, 5-nerved, 

 finely scabrous, 10 mm. long. Mountains: Colo. Mont. 



15. E. Macounii Vasey. Stem 3-10 dm. high, smooth; leaf-blades erect, 

 scabrous, 7-15 cm. long, 2-4 mm. wide; spike slender, 7-12 cm. long; spikelets 

 often solitary at the nodes, 1-3-flowered; lemma scabrous above, 8-10 mm. long, 

 5-nerved. Meadows: Man. N.M. Utah Alta. Plain Submont. 



16. E. curvatus Piper. Stem erect, 6-10 dm. high, glabrous; leaf-blades 

 1-2 dm. long, 5-7 mm. wide, usually flat, scabrous on both sides; spike stout, 

 erect, short-exserted, 5-12 cm. long; lemma 3-5-nerved, sparingly scabroue- 

 hispidulous towards the apex, 8-12 mm. long, acuminate to short-awned; awn 



