This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
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.
Spikelet, exclusive of awn, 1 1/4"-2" long.
Awn not 1" long, shorter than the scale; outer scales 1 1/2 "-2".
Awn 3"-4" long, more than twice as long as the scale; outer scales about 1 1/4" in length.
Spikelet, exclusive of awn, 3"-4" long.
Culms nearly naked, leaves all crowded at the base; panicle 2' - 3' long, its branches 1' in
length or less, erect.
Culms leafy to the top; panicle 6'-12', branches 2'-4,' long, spreading.
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.
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.
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.