240 



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



Figure 320.— Ag 



ropyron pri 

 Calif 



nglei, 

 ) 



X 1. (Pringle 504, 



scabrous, about 2 mm. long; glumes 

 rather narrow, about 3-nerved on the 

 exposed side, 7 to 8 mm. long, taper- 

 ing into a straight awn about 5 mm. 

 long; lemmas tapering into a sca- 

 brous, strongly divergent awn 1.5 to 

 2.5 cm. long; palea 10 to 12 mm. long. 

 % —Stony slopes, 2,500 to 3,500 

 m., in the Sierra Nevada, Calif. 



17. Agropyron scribneri Vasey. 

 Spreading wheatgrass. (Fig. 321) 

 Culms tufted, prostrate or decum- 

 bent-spreading, often flexuous, 20 to 

 40 cm. long; blades flat or, especially 

 on the innovations, loosely involute, 

 more or less pubescent, mostly basal, 

 the 2 or 3 culm blades usually less 

 than 5 cm. long, 1 to 3 mm. wide; 

 spike long-exserted, often nodding or 

 flexuous, dense, 3 to 7 cm. long, the 

 rachis disarticulating at maturity, the 

 internodes glabrous, 3 to 5 mm. long, 

 or the lowermost longer; spikelets 3- 

 to 5-flowered, the rachilla internodes 

 minutely scabrous, about 2 mm. long; 

 glumes narrow, one obscurely nerved, 

 the other with 2 or 3 distinct nerves, 

 tapering into a divergent awn similar 

 to the awns of the lemmas; lemmas 

 nerved toward the tip, tapering to a 

 strongly divergent awn 1.5 to 2.5 cm. 

 long; palea a little longer than the 

 body of the lemma, the apex with 2 

 short slender teeth. % — Alpine 

 slopes, 3,000 to 4,000 m., Montana 

 and Idaho to New Mexico and Cali- 

 fornia. Characterized by the hard 

 leafy basal tussock with slender 

 spreading flexuous culms. 



18. Agropyron spicatum (Pursh) 

 Scribn. and Smith. Bluebunch 

 wheatgrass (Fig. 322.) Green or 

 glaucous; culms tufted, often in large 

 bunches, erect, 60 to 100 cm. tall; 

 sheaths glabrous; blades flat to loosely 

 involute, 1 to 2 mm., sometimes to 4 

 mm., wide, glabrous beneath, pubes- 

 cent on the upper surface; spike slen- 

 der, mostly 8 to 15 cm. long, the 

 rachis scaberulous on the angles, the 

 internodes 1 to 2 cm. long, or the 



Figure 321. — Agropyron scribneri, X 1. (Shear 1179, 

 Colo.) 



