256 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Figure 502.— Distribution of 

 Elymus villosus. 



17. Elymus villosus Muhl. (Fig. 501.) Culms tufted, ascending, 

 slender, 60 to 100 cm tall; sheaths glabrous to sparsely pilose; blades 

 flat, lax, pubescent on upper surface, glabrous or scabrous beneath; 

 spike drooping, dense, 5 to 12 cm long; glumes subsetaceous, spread- 

 ing, distinctly nerved above the firm cylindric 

 nerveless divergent or somewhat bowed-out 

 base, hirsute, 12 to 20 mm long; lemmas nerved 

 toward the tip, hispidulous to hirsute, 7 to 8 

 mm long, about 1.2 mm across the back, the 

 straight slender awn 1 to 3 cm long. % {E. 

 striatus, American authors, not Willd. Moist 



or dry woods and shaded slopes, Vermont to 

 North Dakota and Wyoming, south to North 



Carolina, Alabama, and Texas (fig. 502). E. arkansanus Scribn. and 



Ball is a form with glabrous or scabrous spikelets. 



18. Elymus interruptus Buckl. (Fig. 503.) Culms erect, 70 to 130 

 cm tall; sheaths glabrous; blades flat scabrous, 5 to 12 mm wide; 

 spike flexuous or nodding, 8 to 

 20 cm long; glumes setaceous or 

 nearly so, 1 to 3 cm long, one or 

 both reduced in occasional spike- 

 lets, mostly flexuous or spread- 

 ing, the nerves obscure at least 

 toward the base; lemmas 

 hirsute to scabrous, or glabrous, 

 about 1 cm long, about 2 mm 

 across the back, the awn flexu- 

 ous or divergent, 1 to 3 cm long. 



Figure 504.— Distribution of 

 Elymus interruptus. 



Qi (E. diver siglumis Scribn. and 

 Ball.) — Rich, open moist soil, 

 Wisconsin to North Dakota and 

 Wyoming; Tennessee, Okla- 

 homa, Texas, and northern 

 Mexico (fig. 504). 



19. Elymus canadensis L. 

 Canada wild-rye. (Fig. 505.) 

 Green or of ten glaucous; culms 

 erect, tufted, mostly 1 to 1.5 m 

 tall; sheaths glabrous or rarely 

 pubescent; blades flat, scabrous 

 or sparsely hispid on the upper 

 surface, mostly 1 to 2 cm wide; spike thick and bristly, nodding 

 or drooping, often interrupted below, 10 to 25 cm long, sometimes 

 glaucous; spikelets commonly in threes or fours, slightly spreading; 

 glumes narrow, mostly 2- to 4-nerved, scabrous, sometimes hispid 

 but less so than the lemmas, the bases somewhat indurate and diver- 

 gent but scarcely bowed out, the awn about as long as the body; lem- 



FlGURE 503. 



-Elymus interruptus, X 1. 

 Minn.) 



(Grant 3071, 



