254 



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



Figure 340.- 



/ 



-Elymus pacificus, 

 Calif.) 



X 1. (Davy 6781, 



tipped, 5 to 15 mm. long, those of the 

 upper spikelets usually reduced or ob- 

 solete; lemmas 6 to 10 mm. long, gla- 

 brous, firm, brownish, purplish or 

 tawny, awn-tipped. % — Moist or 

 alkaline soil, at low and medium ele- 

 vations, Montana to Washington, 

 south to western Texas and Baja 

 California. Elymus triticoides var. 



pubescens Hitchc. Sheaths and invo- 

 lute blades pubescent. % — Ore- 

 gon, California, Nevada; rare. 



Elymus triticoides subsp. multi- 

 florus Gould. Plants robust; blades 

 6 to 12 mm. wide; spike compound, 

 the branches mostly short, congested, 

 but sometimes to 5 cm. long; spike- 

 lets 1.5 to 2.5 cm. long. Q[ — Wyo- 

 ming to Washington, Nevada, and 

 California. Intergrades with the spe- 

 cies. 



9. Elymus pacificus Gould. (Fig. 

 340.) Culms low, more or less spread- 

 ing, 10 to 20 cm. tall, with slender ex- 

 tensively creeping rhizomes; blades 

 involute, mostly longer than the 

 culms, pungent-pointed; spike 2 to 5 

 cm. long, the rachis glabrous; spike- 

 lets solitary, few-flowered, 12 to 15 

 mm. long; glumes nerveless, firm, 

 tapering into a short awn; lemmas 

 about 1 cm. long, obscurely nerved, 

 pointed or awn-tipped, the margin 

 very narrowly hyaline. (Agropyron 

 arenicola Davy, not Elymus arenicola 

 Scribn. and Smith.) % — Sandy 

 seacoast, middle California. 



10. Elymus simplex Scribn. and 

 Williams. (Fig. 341.) More exten- 

 sively creeping than E. triticoides, the 

 rhizomes sometimes as much as 5 m. 

 long; culms ascending, 50 to 90 cm. 

 tall ; sheaths crowded, the lower often 

 becoming reddish and papery; blades 

 firm, flat or loosely rolled, strongly 

 nerved; spikes 5 to 20 cm. long; spike- 

 lets as much as 2.5 cm. long, usually 

 distant, solitary or sometimes paired ; 

 glumes subulate-aristate, 1 to 2 cm. 

 long; rachilla villous; lemmas gla- 

 brous, the margins hyaline, awned, 

 the awn 3 to 14 mm. long. % — 

 River banks, alkaline flats, drifting 

 sands, and rocky slopes, southern 

 Wyoming, Colorado, and Utah. Val- 

 uable in erosion control. 



11. Elymus ambiguus Vasey and 

 Scribn. (Fig. 342.) Culms few, loosely 

 tufted, erect, 30 to 70 cm. tall; sheaths 

 glabrous; blades flat to subinvolute, 

 2 to 5 mm. wide, scabrous; spike 

 erect, rather dense, 5 to 15 cm. long; 

 spikelets solitary toward the base and 



