Usually tufted grasses, with flat or convolute leaves and paniculate inflorescence. Spike-lets 1-flowered, broad. Scales 3; the two lower about equal, obtuse or acuminate; the third scale shorter or a little longer, broad, bearing a terminal awn which is early deciduous, the callus at the base of the scale short and obtuse, or a mere scar. Stamens 3. Styles distinct. Stigmas plumose. Grain oblong, free, tightly enclosed in the convolute scale. [Greek, in allusion to the supposed resemblance of these grasses to rice.]

About 24 species, distributed through temperate and subtropical regions, rarely extending into the tropics. Besides the following, some 7 others occur in the western parts of North America. Type species: Oryzopsis asperifolia Michx.

1. Oryzopsis Pungens (Torr.) Hitchc. Slender Mountain-Rice

Fig. 414

Milium pungens Torr.; Spreng. Neue Entd. 2: 102. 1821. Oryzopsis canadensis Torr. Fl. N. Y. 2: 433. 1843. Oryzopsis juncea B.S.P. Prel. Cat. N. Y. 67. 1888. Oryzopsis'pungens Hitchc. Contr. U. S. Nat. Herb. 12: 151. 1908.

Culms glabrous, 6'-2° tall, erect, slender, simple, smooth.

Sheaths shorter than the internodes, usually crowded at the base of the culm; ligule about 1" long, decurrent; blades smooth or scabrous, erect, involute, the basal about one-half the length of the culm, occasionally equalling it, filiform, those of the culm 1'-4' long, the uppermost often very small or reduced to the sheath only; panicle I'-2 1/2' long, the branches \'-\' in length, erect or ascending, the lower half naked; spikelets 1 1/2"-2" long, the outer scales about equal, glabrous, whitish; third scale about the same length or a little longer, pubescent with short appressed silky hairs, the awn less than 1" long.

In dry rocky places, Pennsylvania to Labrador and British Columbia. May-June.

2. Oryzopsis Micrantha (Trin. & Rupr.) Thurb. Small-Flowered Mountain-Rice. Small Indian Millet

Fig. 415

Urachne micrantha Trin. & Rupr. Mem. Acad. St.

Petersb. (VI.) 5: 16. 1842. O. micrantha Thurb. Proc. Phila. Acad. 1863: 78. 1863.

Culms glabrous, 1°-2 1/2° tall, erect, slender, simple, smooth. Sheaths shorter than the internodes; ligule about 1/2" long, truncate; blades erect, scabrous, the basal one-half the length of the culm, less than 1/2" wide, usually more or less involute, the culm leaves 2'-8' long, 1/2"-1" broad, the larger attenuate into a long slender point; panicle 3'-6' long, the branches finally spreading, the lower ones 1 '-2' long, naked for about two-thirds their length; spikelets 1"-1 1/4" long, the outer scales about equal, acute, glabrous; third scale shorter, glabrous, bearing an awn 3"-4" long.

In canons and on dry hills, Saskatchewan to Nebraska, New Mexico and Arizona. June-July.