Trisetum rosei Scribn. & Merr.

Trisetum rosei Scribn. & Merr. Contr. U. S. Nat. Herb 8:289. 1905.
Trisetum Rosei tenerum Scribn. & Merr. Contr. U. S. Nat. Herb. 8: 289. 1905. (Type from
Popocatepetl, Mexico.) Trisetum Rosei f. tenerum Louis-Marie, Rhodora 30: 239. 1928. (Based on T. Rosei tenerum
Scribn. & Merr.)
Perennial; culms densely tufted, puberulent to densely pubescent, 25-50 cm. tall; sheaths glabrous or puberulent; ligule rounded, erose, about 2 mm. long; blades loosely involute, erect, glabrous or puberulent, rather firm or leathery, sharp-pointed, 1-2 mm. wide; panicle rather loosely spikelike, more or less interrupted, mostly 5-10 cm. long, the axis and branches densely villous; spikelets 4-6 mm. long, the rachilla-joint villous, about 1 mm. long; glumes glabrous or a little scaberulous, rather prominently ciliate on the keels, rather broad, the second a little broader and a little longer; lemmas densely villous all over, the callus-hairs not distinguishable from the hairs above, the awn spreading, exserted, somewhat plumose.
Type locality: Mount Popocatepetl. Mexico (Rose 6016). Distribution: Alpine regions of the high mountains of southern Mexico.