MANUAL OF THE GRASSES OF THE UNITED STATES 



99 



11. HESPEROCHLOA (Piper) Rydb. 



(Included in Festuca L. in Manual, ed. 1) 



Spikelets 3- to 5-flowered, the rachilla disarticulating above the glumes and 

 between the florets; glumes subequal or the second longer than the first, 

 shorter than the first floret, lanceolate, acute, the first 1-nerved, the second 

 3-nerved ; lemmas rounded on the back, acute or acuminate, awnless, 5-nerved ; 

 palea as long as the lemma, scabrous-ciliate on the keels; stigmas sessile, 

 long and slender; grain beaked, bidentate at the apex. Densely tufted, 

 dioecious, rhizomatous perennial with firm, narrow, flat or loosely involute 

 blades, and narrow erect panicles. Type species, Hesperochloa kingii. Name 

 from Greek esperis, western, and chloa, grass. 



1. Hesperochloa kingii (S. Wats.) 



Rydb. (Fig. 114.) Culms in large 

 dense clumps, erect, the rhizomes 

 usually wanting in herbarium speci- 

 mens; sheaths smooth, striate, the 

 lower reddish brown in age; blades 

 firm, flat, or becoming loosely in- 

 volute, scabrous on the margins, 3 

 to 6 mm. wide; panicles 7 to 20 cm. 

 long, the branches short, appressed, 

 floriferous nearly to the base, the 

 staminate inflorescences denser with 

 somewhat larger spikelets than the 

 pistillate; spikelets 7 to 12 mm. long; 

 glumes thin, shining, acute or sub- 

 obtuse, the first 3 to 4 mm. long, 

 the second 4 to 6 mm. long; lemmas 

 5 to 8 mm. long, acute or acuminate, 

 scabrous. Ql (Festuca con finis Va- 

 sey; F. kingii Cassidy.) — Dry moun- 

 tains and hills, 2,000 to 3,500 m., 

 Oregon to southern California, east 

 to Montana, Nebraska, and Colorado. 



Figure 114. — Hesperochloa kingii. Plant, X V%\ spike- 

 let, X 5. (Osterhout 1897, Colo.) 



12. POA L. Bluegrass 



Spikelets 2- to several-flowered, the rachilla disarticulating above the 

 glumes and between the florets, the uppermost floret reduced or rudimentary; 

 glumes acute, keeled, somewhat unequal, the first usually 1-nerved, the 

 second usually 3-nerved; lemmas somewhat keeled, acute or acutish, rarely 

 obtuse, awnless, membranaceous, often somewhat scarious at the summit, 

 5-nerved (intermediate nerves, that is, the pair between the keel and the mar- 

 ginal nerves, rarely obsolete), the nerves sometimes pubescent, the callus or 

 base of the lemma in many species with scant to copious cottony hairs, termed 

 "web." Low or rather tall slender annuals or usually perennials with spikelets 



