408 GRAMINE.E. (GRASS FAMILY.) 



2. S. pennata, L., var. Neo-Mexicana, Thurber. — Easily distin- 

 guished by the awns, which are 6 inches or more long, twisted for l£ to 2 inches 

 below, the upper part flat and beautifully plumose-pennated . — Gram. Mex. 

 Bound, ined. Extending into S. W. Colorado from New Mexico and Texas. 



* * Awn not plumose, often strongly pubescent. 

 •4- Panicle loose, open. 



3. S. Richardsonii, Link. Stein l£ to 2 feet high, slender: panicle 4 to 

 5 inches long, with slender few-flowered branches ; callus short and blunt : outer 

 glumes pointless, nearly equal, about equalling the pubescent flowering glume ; 

 awn 6 to 8 lines long. — Mountains of Montana, Scribner, and northward ; 

 Manitoba and north shore of Lake Superior, Macoun ; also in Maine. 



4. S. COmata, Trin. & Rupr. Stems 1 to 4 feet high, stout, mostly scabrous : 

 leaves roughened, the radical 4 or -J the length of the stem: panicle included 

 at base by the upper sheath, 8 to 12 inches long ; callus pointed: outer glumes 

 nearly equal, with a long subulate point : flowering glume pubescent with coarse 

 hairs : awn 4 to 6 inches long, scabrous especially above, shining, variously 

 curled and twisted. — Watson, Bot. King Exped. 380. From the Upper 

 Missouri to California, New Mexico, and Nebraska. 



-»- -i- Panicle narroiv, contracted. 



5. S. spartea, Trin. Stems 1| to 3 feet high, rather stout: callus pun- 

 gently pointed, villous-bearded (when mature) : glumes lanceolate, slender subu- 

 late-pointed, greenish, longer than the palets which are linear and pubescent 

 below. — From Colorado to the Upper Missouri, thence eastward to Illinois 

 and Michigan. 



6. S. viridula, Trin. Stems l£ to 5 feet high, with numerous withered 

 sheaths at base : panicle 6 to 18 inches long; callus very short: glumes ovate, 

 bristle-pointed, sometimes tinged with purple : lower palet with short scattered 

 hairs which form a rather irregular crown, and with 2 very minute hyaline teeth : 

 awn 1 to 1| inches long, usually twice bent, pubescent below and scabrous 

 above. — Watson, Bot. King Exped. 380. From Colorado to California, 

 Oregon, the Upper Missouri, and British America. 



15. ORYZOPSIS, Michx. Mountain Rice. 



Perennials, with rigid leaves and a narrow raceme or panicle. Spikelets 

 rather large. 



1. O. micrailtha, Thurber. Leaves linear-setaceous, involute : branches 

 of the panicle in pairs, many-flowered; spikelets shining, florets smooth, a little 

 shorter than the linear acutish glumes : awn about thrice longer than the glumes : 

 anthers naked at apex. — Steud. Glum. 122. Colorado and southward. 



2. O. CUSpidata, Benth. Stems 1 to 2 feet high, rather rigid and some- 

 what scabrous: leaves narrow, involute, elongated (2 to 18 inches): panicle 

 frequently included at base, dichotomously branched ; the spikelets solitary upon 

 capillary peduncles : outer glumes more or less purple, pubescent, attenuate- 

 rostrate: flowering glumes rigid, densely covered with long white silky hairs: the 

 stout nearly straight awn mostly longer : palet rigid : anthers bearded at apex. 

 — Eriocoma cuspidata, Nutt. From the Sierras eastward to Missouri and 

 Texas. 



