MANUAL OF THE GRASSES OF THE UNITED STATES 



107 



ted, 5 to 12 cm. long; spikelets mostly 

 5- to 10-flowered, the pistillate con- 

 spicuously cobwebby, the lemmas 5 

 to 6 mm. long, acuminate, copiously 

 long webby at base, the strongly 

 compressed keel and lateral nerves 

 ciliate-f ringed along the lower half; 

 staminate lemmas glabrous or with 

 a scant web at base. % — Prairies 



sively creeping rhizomes, and also 

 long runners creeping over the sand, 

 15 to 40 cm. tall; sheaths tawny, 

 papery; blades involute, subflexuous; 

 panicle contracted, sometimes dense 

 and spikelike, 5 to 12 cm. long, pale 

 or tawny; spikelets about 12 mm. 

 long, about 5-flowered; glumes 3- 

 nerved, or the second indistinctly 5- 



Figurb 121. — Poa arachnifera. Plant and pistillate (?) and staminate (c?) panicles, X 1; pistillate (Q») and 



staminate (cf) florets, X 10. (Blackman, Tex.) 



and plains, southern Kansas to Texas 

 and Arkansas; introduced eastward 

 to North Carolina and Florida; 

 Idaho. Sometimes cultivated for win- 

 ter pasture. 



8. Poa macrantha Vasey. (Fig. 

 122.) Plants dioecious; culms erect 

 from a decumbent base, with exten- 



nerved, about 8 mm. long; lemmas 

 about 8 mm. long, short-webbed at 

 base, pubescent on the keel and 

 marginal nerves below, slightly sca- 

 brous on the keel above; pistillate 

 florets with abortive stamens. % 

 — Sand dunes along the coast, Wash- 

 ington to northern California. 



