MANUAL OF THE GRASSES OF THE UNITED STATES 



western Mexico. Alpine plants lower, 

 and with shorter denser commonly 

 purplish spikes, resemble A. sub- 

 secundum var. andinum, but the 

 spikelets are awnless. They have been 

 referred to A. violaceum (Hornem.) 

 Lange, an Arctic species, and to A. 

 biflorum (Brignoli) Roem. and Schult. 



239 



Figure 318. — Agropyron latiglume, X 3. (Type.) 



14. Agropyron latiglume (Scribn. 

 and Smith) Rydb. (Fig. 318.) Culms 

 loosely tufted, curved or geniculate 

 below, 20 to 50 cm. tall; blades flat, 

 short, 3 to 5 mm. wide, short-hirsute 

 on both surfaces, rarely glabrous or 

 nearly so beneath; spike mostly 3 to 

 7 cm. long, rarely longer; spikelets 

 usually closely imbricate; glumes 

 broad, flat, thin-margined, unsym- 

 metrical and slightly notched at 

 summit, awn-tipped; lemmas com- 

 monly appressed-pubescent, awnless 

 or awn-tipped. 01 — Alpine mead- 

 ows, open slopes, mostly at high 

 altitudes, Montana, Wyoming, and 

 Colorado to Labrador and Alaska. 



15. Agropyron bakeri E. Nels. 

 Baker wheatgrass. (Fig. 319.) Re- 

 sembling A. sub secundum; culms 

 erect, mostly 50 to 100 cm. tall, 

 rather loosely tufted; spike mostly 

 5 to 12 cm. long, the spikelets rather 

 loosely imbricate; awns divergently 

 curved when dry, 1 to 4 cm. long. 

 % — Open slopes, upper altitudes, 

 northern Michigan ; Alberta to Wash- 

 ington, Oregon, and New Mexico. 



16. Agropyron prmglei (Scribn. 

 and Smith) Hitchc. (Fig. 320.) Culms 

 tufted, decumbent at base, 30 to 50 



Figure 319.- 



-Agropyron bakeri, X 1. (Hitchcock 

 1686, Colo.) 



cm. tall, the basal sheaths soft and 

 papery; blades flat or loosely involute, 

 mostly less than 10 cm. long, 1 to 3 

 mm. wide; spike more or less flexuous, 

 4 to 7 cm. long, the rachis scabrous 

 on the angles, slender, the middle in- 

 ternodes usually 8 to 10 mm. long; 

 spikelets mostly 3 to 7 in each spike, 

 rather distant, the lower and middle 

 ones (excluding awns) about as long 

 as two internodes, mostly 3- to 5- 

 flowered, the rachilla joints minutely 



