GRASS FAMILY' 45 



19. ORYZOPSIS Michx. Mountain Rice. 



Tufted perennials. Intlorescence paniculate with racemose branches. 

 Spikelets l-tto\vered, broad; flowers perfect. Empty glumes subequal, acute. 

 Lemma broad, indurate, convolute, with a short and obtu.se callus at the base, 

 ending in a terminal, early deciduous, mostly straight awn. Styles distinct: 

 stigmas plumose. Grain oblong, free. 



I^emma ^I'T-'irous, or pubescent with short appressed hairs. 



.Si)ikelets, exclusive of the awn, 2.5-5 mm. long: leaves slender and involute. 



.\wii less than 2 mm. long, much shorter than the glume; outer glumes 3-4 ram. 



long. 1. O. pungens. 



Awn 4-8 mm. long, much longer than the glume. 



Inflorescence very narrow, with short erect branches; outer glumes 3-5 mm. 



long. 2. O. eiigua. 



Inflorescence at length open, with long spreading or reflexed branches ; outer 

 glume about 2.5 mm. long. 3. O. micranlha. 



Spikelets, exclusive of the awn, 6-8 mm. long; leave.s broad and usually flat. 



4. O. asperifolia. 

 Lemma with long loose hairs. 



Inflorescence open; plant 3-6 dm. high. 5. O. Bloomeri. 



Inflorescence narrow and spike-like; plant 1-3 dm. high. 6. O. Webberi. 



1. O. pungens (Torr.) Hitchc. Tufted perennial; stem glabrous, 1.5-3 dm. 

 tall, simple; sheaths shorter than the internodes, smooth; leaf-blades smooth or 

 scabrous, the lower 1-2 dm. long, the upper 3-10 cm. long; panicle 3-6 cm. long; 

 branches erect or ascending; spikelets 3-4 mm. long; empty glumes glabrous, 

 whitish, faintly nerved, acute; lemma strigose, ellipsoid. 0. canadensis Torr. 

 O. juncea B.S.P. Dry rocky places: Que. — Pa. — ^S.D. — -B.C. Boreal — Moni. 

 My-Je. 



2. O. exigua Thurb. Densely tufted perennial; stem 1..5-4 dm. high; 

 panicle 2-6 cm. long; empty glumes 4- .3 mm. long, acute or abrui)tly acuminate, 

 the first 1-nerved, the second 3-neryed; lemma sparingly strigose; awn slightly 

 twisted below, 4-6 mm. long. Hills and mountain sides: Mont, — ^Colo. — Ore. 

 — Wash. Mont. — Subalp. Je-Au. 



3. O. micrantha (Trin. & Rup.) Thurb. Somewhat tufted perennial; stem 

 glabrous, 3-7 dm. tall, slender; leaf-blades erect, scabrous, less than 1 mm. wide, 

 usually involute, the lower 2-3 dm. long; panicle 8-15 cm. long; empty glumes 

 2-2.5 mm. long, glabrous, acute; lemma a little shorter, glabrous, shining; awn 

 6-8 mm. long. Hillsides and among bushes: Sask. — Neb. — X.M. — -Ariz. — ■ 

 Mont. Plain — Mont. Je-Au. 



4. O. asperifolia Michx. Tufted perennial; stem 3-5 dm. high, simple, 

 usually scabrous; leaf-blades erect, scabrous, 1-4 dm. long, 4-10 mm. wide; 

 panicle .5-8 cm. long, narrow, spike-like; empty glumes glabrous, 6-8 mm. long, 

 many-nerved, apiculate; lemma whitish, sparingly hairy, except a ring of dense 

 hairs at the base; awn 7-10 mm. long. Woods: N.S. — Pa. — ^Minn. — N.M. — 

 B.C. Mont. My-Je. 



5. O. Bloomeri (Bolander) Ricker. Tufted perennial; stem 3-6 dm. high, 

 glabrous; leaf-blades involute, 1-2 dm. long; panicle 1-2 dm. long, open but 

 rather narrow; empty gliunes dull green, tinged with purple, 6-7 mm. long, 

 acuminate; lemma 5 mm. long, clothed with spreading or ascending long white 

 hairs; awn twisted and bent, about 2 cm. long. 0. ca/luca (Scribn.) Beal. Erio- 

 cotna caduca Rydh. Hills: Mont. — -Colo. — Calif. Submont. Jl. 



6. O. Webberi (Thurb.) Benth. Densely tufted perennial; stem 1-3 dm. 

 high, wiry; lower sheaths crowded, glabrous; leaf-blades very narrow, stiff, in- 

 volute, the lower 5-10 cm. long, glaucous; panicle dense and spike-like, 2-10 

 cm. long; branches short and erect; emi)ty glumes 8 mm. long, acuminate, often 

 purple-tinged; lemma 6 mm. long, copiously long-hairy; awn 4 mm. long, very 

 slender, soon caducous. Arid regions: Calif. — Colo. Son. My-Jl. 



20. ERIOCOMA Xutt. Ixdi.\n xMillet, Wild Rice. 



Densely tufted i>erennials with involute leaves. Inflorescence cymosely 

 and divaricately branched. Spikelets 1-flowered; flower perfect. Emjjty glumes 

 2, membranous, .somewhat scarious, acuminate. Lemma rather broad, indurate 



