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



as long as the lemma. % — Plains 

 and dry open ground, Manitoba to 

 Alberta, south to Minnesota, Wyo- 

 ming, Colorado, and Idaho. 



8. Calamagrostis cainii Hitchc. 

 (Fig. 430.) Culms 30 to 60 cm. tall, 

 slender, erect; blades as much as 35 

 cm. long, 1 to 2 mm. wide, flat or 

 loosely involute, attenuate, scabrous 

 above; panicles 6 to 10 cm. long, pale 

 or purple-tinged, the slender ascend- 

 ing branches 1 to 2 cm. long, few- 

 flowered; glumes narrow, acuminate, 

 5 to 6 mm. long; lemma acuminate or 

 minutely dentate, the nerves some- 

 times extending into short mucros, 

 the callus -hairs about 1 mm. long; 

 awn attached about 1 mm. above the 

 base, geniculate, a little longer than 

 the glumes; rachilla very short, the 

 hairs 1 to 2 mm. long. % — Shrub- 

 by summit and open slopes of Mount 

 LeConte, above 5,000 feet, Tenn. 



Figure 428. — Calama- 

 grostis purpurascens. 

 Panicle X 1; glumes 

 and floret, X 10. 

 (Goodding 375, Wyo.) 



third as long as the lemma. % (C. 

 vaseyi Beal.) — Rocks and cliffs, 

 Greenland to Alaska, south to Que- 

 bec, South Dakota (Black Hills), 

 Colorado, and California. 



7. Calamagrostis montanensis 

 Scribn. Plains reedgrass. (Fig. 

 429.) Culms stiffly erect, scabrous be- 

 low the panicle, usually 20 to 40 cm. 

 tall, sometimes taller, with slender 

 creeping rhizomes; lower sheaths 

 rather papery, smooth; blades erect, 

 mostly less than 2 mm. wide, more or 

 less involute, scabrous, sharp-pointed ; 

 panicle dense, erect, more or less in- 

 terrupted, usually pale, 5 to 10 cm. 

 long; spikelets 4 to 5 mm. long, the 

 pedicels very scabrous; glumes acu- 

 minate, scabrous; lemma nearly as 

 long as the glumes, finely 4-toothed, 

 the awn attached about 1 mm. above 

 base, about equaling the lemma, 

 slightly geniculate and protruding 

 from side of glumes; palea nearly as 

 long as the lemma; hairs of callus and 

 rachilla rather abundant, about half 



Figure 429. — Calamagrostis montanensis. Panicle, 

 X 1; glumes and floret, X 10. (Scribner 363, Mont.) 



