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



along Fire Hole River, Yellowstone 

 Park, Wyo. 



12. Agrostis elliottiana Schult. 

 (Fig. 471.) Annual; culms slender, 

 erect or decumbent at base, 10 to 

 40 cm. tall; blades flat, about 1 mm. 

 wide; panicle finally diffuse, about 

 half the entire height of the plant, 

 the branches capillary, fascicled, the 

 spikelets toward the ends of the 

 branchlets, the whole panicle break- 

 ' ing away at maturity; spikelets 1.5 



Figure 469.— Agrostis humilis. Panicle, X 1; glumes tO 2 mm. long; glumes acute '. lemma 



and floret, X 5. (Type.) 



mm. long; lemma nearly as long as 

 the glumes, awnless; palea about 

 two-thirds as long as lemma. % 

 — Bogs and alpine meadows at high 

 altitudes, Wyoming and Colorado to 

 Washington, Oregon, and Nevada. 



Figure 470. — Agrostis rossae. Panicle, X 1; glumes 

 and floret, X 5. (V. H. Chase 5740, Yellowstone 

 Natl. Park, Wyo.) 



11. Agrostis rossae Vasey. (Fig. 



470.) Annual, erect, leafy and branch- 

 ing at base, 10 to 19 cm. tall; sheaths 

 rather loose; blades flat, 1 to 2.5 cm. 

 long, 1 to 2 mm. wide; panicle 3.5 

 to 6 cm. long, usually contracted, the 

 capillary scabrous purplish branches 

 in relatively distant fascicles, nar- 

 rowly ascending, naked at base; 

 spikelets 2 to 2.5 mm. long; glumes 

 acuminate; lemma- 1.5 to 1.6 mm. 

 long, minutely toothed, aAvnless ; palea 

 very minute. O — Alkali soil near 

 hot springs, Upper Geyser Basin and 



Figure 471. — Agrostis elliottiana. Panicle, X 1; 

 glumes and floret, X 5. (Johnson, Miss.) 



1 to 1.5 mm. long, minutely toothed, 

 awned below the tip, the awn very 

 slender, flexuous, delicately short- 

 pilose, 5 to 10 mm. long, sometimes 

 falling at maturity; palea wanting. 

 O — Fields, waste places, and open 

 ground, Maryland to Kansas, south 

 to Georgia and eastern Texas; intro- 

 duced in Maine and Massachusetts; 

 Yucatan. 



Figure 472. — Agrostis exigua. Panicle, X 1; glumes 

 and floret, X 5. (Type.) 



