MANUAL OF THE GRASSES OF THE UNITED STATES 



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lowermost 2,5 cm.; spikelets distant, 

 not as long (excluding the awns) as 

 the internodes or slightly longer, 

 mostly 6- to 8-flowered, the rachilla 

 joints scaberulous, 1.5 to 2 mm. long; 

 glumes rather narrow, obtuse to 

 acute, rarely short-awned, about 4- 

 nerved, usually about half as long as 

 the spikelet, glabrous or scabrous on 

 the nerves; lemmas about 1 cm. long, 

 the awn strongly divergent, 1 to 2 

 cm. long; palea about as long as the 

 lemma, obtuse. 21 — Plains, dry 

 slopes, canyons and dry open woods, 

 northern Michigan to Alaska, south 

 to western South Dakota, New Mex- 

 ico, and California. A smaller form 

 with smaller spikelets, found in desert 

 regions of the Great Basin has been 

 differentiated as A. vaseyi Scribn. and 

 Smith. A. spicatum var. pubescens 

 Elmer. Culms and foliage pubescent. 

 01 — Washington and Idaho. 



Figure 323. — Agropyron inerme, X 

 1. (Horner 571, Wash.) 



19. Agropyron inerme (Scribn. and 

 Smith) Rydb. Beardless wheat- 

 grass. (Fig. 323.) Differing from A. 

 spicatum in the awnless spikelets. % 

 (A. spicatum var. inerme Heller.) — 

 Dry plains and hills, Montana to 

 British Columbia, south to Utah, 

 Wyoming, western Nebraska, and 

 eastern Oregon; Texas. Closely re- 

 lated to A. spicatum, but very differ- 

 ent in appearance because awnless. 



Figure 322. — Agropyron spicatum, X 1. (Vasey, 

 Wash.) 



Figure 324. — Agropyron arizonicum, X 1. (Type.) 



20. Agropyron arizonicum Scribn. 

 and Smith. (Fig. 324.) Resembling A. 

 spicatum, usually taller and coarser; 



