40 GRAMINACEAE (GRASS FAMILY) 



Q. Seed tightly inclosed by the ovary; stamen i; lemma with ^ very small 

 dorsal awn. — (Gk. kinna ~ some kind of a grass.) Cinna (indian reed) 



QQ. Seed loosely inclosed by the ovary; stamens 2-3; lemma awnless. — 

 (Gk. spora = a seed, ballein = to cast forth; the grain is deciduous.) 



Sporobolus (dropseed) 



STIPA (Needle Grass) 



Perennial, tufted. Leaves often rolled up. Spikelets in a terminal 

 panicle. Glunies persistent, keeled, unawned or rarely with a slender awn. 

 Lemma narrow, rigid, convolute, with callus at base, awned ; callus bearded ; 

 awn terminal, twisted, geniculate. Palet 2-veined. Stamens 3. Grain 

 cylindric, included, often burying itself in the soil by the twisting and un- 

 twisting of the awn. — In dry soil. Range grasses. (Gk. stupe = tow; 

 from the towlike plumes of some species.) 



A. Awn 7.5-20 cm. long. 



B. Glumes 20-30 mm. long including the point, s-veined; lemma without crown of 

 hairs at apex. E. S. comata (needle grass) 



BB. Glumes 16-20 mm. long, 3-veined; lemma with crown of hairs at apex. E. 



S. setigera (bear grass) 

 AA. Awn 5 cm. or less long. 



C. Awn only slightly pubescent or scabrous. 



D. Callus acute or acuminate, about i ram. long. 

 E. Panicle 15-25 cm. long; lemma and its callus 6-7 mm. long; palet \ as long as 

 the lemma. 

 F. Sheaths smooth; awn 3.5-6 cm. long. E. S. nelsoni 



FF. At least the lower sheaths pubescent; awn 2-3 cm. long. E. S. wllliamsil 

 EE. Panicle 5-12 cm. long; lemma and its callus about 4 mm. long; palet | as 

 long as the lemma. W. C. E. S. columbiana 



DD. Callus obtuse, very short. E. S. lemmoni 



CC. Awn plumose. 

 G. Ligule I mm. long or less. 

 H. Sheaths pubescent. 

 I. Awn smooth or rough but not pubescent. E. 



S. viridtila (feather needle grass) 



n. Awn pubescent to the second bend. E. S. elmeri 



HH. Sheaths glabrous. E. S. occidentalis (western needle grass) 



GG. Ligule 2-4 mm. long. E. S. thurberiana 



ORYZOPSIS (Mountain Rice) 



Perennial, tufted. Spikelets in a narrow lax few-flowered panicle; 

 rachilla not prolonged beyond the palet. Glumes persistent, convex on the 

 back, obtuse or abruptly acute. Lemma wide, obtuse-truncate, terminat- 

 ing in an awn ; awn deciduous, simple, more or less bent near the base. 

 Palet 2-keeled. Stamens 3. Grain oblong-ellipsoid, free. — (Gk. oryza = 

 rice, opsis = form.) 



A. Lemma densely covered with conspicuous long white hairs; panicle loose; not 

 alpine. 

 B. Leaf blade smooth; lemma narrowly elliptic; awn 8-12 mm. long. E. 



O. bloomeri 



