MANUAL OF THE GRASSES OF THE UNITED STATES 



261 



Rich, open moist soil, Michigan to 

 North Dakota and Wyoming; Ten- 

 nessee, Arkansas, Oklahoma, Texas, 

 New Mexico. 



22. Elymus canadensis L. Canada 

 wild-rye. (Fig. 353.) Green or often 

 glaucous; culms erect, tufted, mostly 

 1 to 1.5 m. tall; sheaths glabrous or 

 rarely pubescent; blades flat, sca- 

 brous 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 divergent but scarcely bowed 

 out, the awn about as long as the 

 body; lemmas scabrous-hirsute to 

 hirsute-pubescent, rarely glabrous, 

 strongly nerved above, the awn di- 

 vergently curved when dry, 2 to 3 

 cm. long. 91 — River banks, open 

 ground, and sandy soil, Quebec to 

 southern Alaska, south to North 

 Carolina, Missouri, Texas, Arizona, 

 and northern California. E. wiegandii 

 Fernald has been differentiated on 

 lax inflorescence, shorter glumes, and 

 thin flat blades, pilose on the nerves. 

 These characters are found to be 

 rarely coordinated, loose flexuous 

 spikes being not infrequent in humid 

 regions, rarer in dry areas; pilose 

 blades are very rare. Elymus cana- 

 densis var. robtjstus (Scribn. and 

 Smith) Mackenz. and Bush. Differ- 

 ing in the stouter and denser only 

 slightly nodding very bristly spikes. 

 % — Prairies, Massachusetts to 

 Montana, south to Kentucky, Mis- 

 souri, Texas, and Arizona. Elymus 

 canadensis var. brachystachys 

 (Scribn. and Ball) Farwell. Lemmas 

 glabrous or nearly so. % — Moist 

 open or partly shaded ground, Ar- 

 kansas, Oklahoma, Texas, and New 

 Mexico; Mexico. Grades into E. 

 canadensis; many specimens of E. 

 canadensis from Kansas to North 

 Dakota have sparingly hirsute lem- 



mas, showing a transition to this 

 variety. 



23. Elymus riparius Wiegand. (Fig. 

 354.) Culms rather slender, erect, 1 

 to 1.5 m. tall; sheaths glabrous; 

 blades rather thin, flat, 5 to 15 mm. 

 wide, scabrous; spike somewhat 

 nodding, 7 to 20 cm. long; glumes 

 narrow, about 1 mm. wide at the 

 middle, 2- to 4-nerved, somewhat 

 indurate but scarcely bowed out at 

 base; lemmas minutely hispidulous 

 to glabrous, the awn straight, mostly 

 2 to 3 cm. long. % — River banks 



Figure 354. — Elymus riparius, X 1. (Woodward, 

 Conn.) 



and low ground, Quebec and Maine 

 to Wisconsin and Nebraska, south to 

 North Carolina, Arkansas, and Kan- 

 sas. Differing from E. virginicus var. 

 glabriflorus in the nodding spike and 

 less indurate glumes; from E. cana- 

 densis in the straight awns and 

 narrower and somewhat more in- 

 durate glumes. When the ranges of 

 E. riparius and E. canadensis coin- 

 cide the latter may be distinguished 

 by the hirsute lemmas. 



24. Elymus virginicus L. Virginia 

 wild-rye. (Fig. 355.) Culms tufted, 

 erect, 60 to 120 cm. tall; sheaths 

 glabrous; blades flat, scabrous, mostly 

 5 to 15 mm. wide; spike usually erect, 

 often partly included, 5 to 15 cm. 

 long; glumes strongly nerved, firm, 

 indurate, yellowish, nerveless and 

 bowed out at base leaving a rounded 

 sinus, broadened above (1.5 to 2 

 mm. wide), scabrous, the apex some- 



