MANUAL OF THE GRASSES OF THE UNITED STATES 



421 



12. Oryzopsis hymenoides (Roem. and Schult.) Ricker. Indian 

 ricegrass. (Fig. 881.) Culms densely tufted, 30 to 60 em tall: 

 ligule about 6 mm long, acute; blades slender, involute, nearly as long 

 as the culms; panicle diffuse, 7 to 15 cm long, the 

 slender branches in pairs, the branchlets dicho- 

 tomous, all divaricately spreading, the ultimate 

 pedicels capillary, flexuous; glumes about 6 to 7 

 mm long, puberulent to glabrous, rarely hirsute, 

 papery, ovate, 3- to 5-nerved, abruptly pointed: 

 lemma fusiform, turgid, 

 about 3 mm long, nearly 

 black at maturity, densely 

 long-pilose with white 

 hairs 3 mm long; awn 

 about 4 mm long, straight, 

 readily deciduous. % — 

 Deserts and plains, med- 



?ium altitudes, Manitoba 

 to British Columbia, south to Texas, California, 

 and northern Mexico (fig. 882) 

 Nassella major (Trin. & Rupr.) Desv. Slender 

 ^b™ ^^°! y x P i%ovit tufted perennial; blades narrow, flat or loosely 

 xo'. (Hiiiman, xeV.) ' involute ; panicle narrow, 3 to 5 cm long, the few 

 branches appressed, 1 to 1 .5 cm long ; glumes 4 mm 

 long, awn-pointed; mature lemma flattish, obovate-oblong, gibbous 

 at apex, smooth and shining, 2 mm long; awn geniculate, 1 cm long, 

 soon deciduous. — Ballast, Portland, Oreg. Introduced from Chile. 



Figure 879.— Distribution of 

 Oryzopsis bloomeri. 



83. PIPTOCHAETIUM Presl 



Spikelets 1-flowered, disarticu- 

 lating above the glumes, the callus 

 of the floret short, acutish, usually 

 bearded; glumes about equal, broad, 

 ovate, convex on the back, thin, 

 abruptly acuminate : fruit brown or 



Figure 882— Distribution of 



Oryzopsis hymenoides. 



dark gray, coriaceous, obovate, 

 shorter than the glumes, glabrous 

 or hispid above the callus, often 

 minutely striate, sometimes tuber- 

 culate near the summit, the lemma 

 turgid, usually somewhat com- 

 pressed and keeled on the back, gibbous near the summit back of 

 the awn, the edges not meeting but clasping the sulcus of the palea, 



Figure SSI.— Or yzopsis hymenoides. Panicle, X 

 1; floret, X 5. (Mearns 2583, Wyo.) 



