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



but not stiff, few-flowered, the axis only a few cm long, the branches 

 ascending or appressed, or the lower more or less curved or flexuous; 

 first glume 8 to 10 mm long, the second about twice as long; lemma 

 terete, 12 to 15 mm long, only slightly narrowed above, glabrous or 



Figure 972.— Aristida roemeriana, X 1. (Swallen 1585, Tex.) 



the upper part scaberulous but scarcely tuberculate-scabrous in lines 

 as in A. purpurea; awns about equal, divergent, 6 to 8 cm long. % — 

 Plains and foothills, North Dakota to Montana, south to Texas, 

 Arizona, and northern Mexico (fig. 976). Aristida longiseta var. 



rariflora Hitchc. Differing in 

 the few-flowered panicles with 

 capillary flexuous branches bear- 

 ing 1 or 2 spikelets. % — Texas 

 to Colorado and Arizona. 



Aristida longiseta var. ro- 

 busta Merr. Taller and more ro- 

 bust, 30 to 50 cm tall, the blades 



Figure 974.— Distribution of 

 Aristida wrvjhtii. 



longer and not in conspicuous bas- 

 al tufts, the panicle longer, stiff er, 

 and the branches more stiffly as- 

 cending, the awns mostly 4 to 5 

 cm long. % — Same range but 

 more common northward, extend- 

 ing east to Minnesota and west 

 to Oregon and Washington. 

 27. Aristida fendleriana Steud. Fendler three-awn. (Fig. 977.) 

 Resembling A. longiseta; differing in the numerous short curly blades 

 at the base of the plant, the shorter glumes (the first about 7 mm 

 long), the gradually narrowed lemma, scaberulous on the upper half, 



Figure 973.— Aristida wrightii, X 1. (Ball 1511, Tex.) 



