MANUAL OF THE GRASSES OF THE UNITED STATES 



235 



12 cm. long; spikelets loosely to 

 closely imbricate, 4- to 8-flowered, 

 1 to 1.5 cm. long, the rachilla pubes- 

 cent on the convex side; glumes acute 

 or awn-pointed, scabrous or pubes- 

 cent (usually less pubescent than the 

 lemma), 6 to 9 mm. long; lemmas 

 densely to sparsely pubescent, some- 

 times nearly glabrous, awnless or 

 mucronate, about 1 cm. long; palea 

 about as long as the lemma, obtuse. 

 % — Plains and sandy shores, Mich- 

 igan to British Columbia, south to 



Figtjke 310. — Agropyron dasystachyum, X 1. (Griffiths 488, Wash.) 



cent near the base, obscurely nerved, 

 acuminate, mucronate, sometimes 

 short-awned ; palea scabrous-pubes- 

 cent on the keels. % — Moist, 

 usually alkaline soil, Ontario to Al- 

 berta and British Columbia; New 

 York; Michigan to Washington, south 

 to Tennessee, Texas, Arizona, and 

 northeastern California ; mostly intro- 

 duced east of Iowa and Kansas. 

 Two varieties have been recognized. 

 Agropyron smithii var. molle 

 (Scribn. and Smith) Jones. Lemmas 

 and sometimes glumes more or less 

 pubescent. % — About the same 

 range as the species. Agropyron 

 smithii var. palmeri (Scribn. and 

 Smith) Heller. Lower sheaths pu- 

 bescent. % — Colorado to Utah, 

 south to New Mexico and Arizona. 

 6. Agropyron dasystachyum (Hook.) 

 Scribn. Thickspike wheatgrass. 

 (Fig. 310.) Often glaucous; culms 

 mostly 40 to 80 cm. tall, with creeping 

 rhizomes; blades flat to involute, 1 

 to 3 mm. wide; spike mostly 6 to 



Figure 311. — Agropyron elmeri, X 1. (Type.) 



