Trisetum palmeri Hitchc.

Trisetum palmeri Hitchc. Contr. U. S. Nat. Herb 17:325. 1913.
Culms cespitose, slender, glabrous, 601 00 cm. tall ; sheaths glabrous or somewhat scabrous ; ligule 3-4 mm. long; blades elongate, nearly or quite equaling the panicle, 1-3 mm. wide, soon involute, scabrous; panicle loose, narrow, 10-20 cm, long, the branches several in rather distant whorls, ascending, the shorter ones spikelet-bearing nearly to the base, the longer 5 cm. long, naked below; spikelets, excluding the awns, 5-6 mm. long, 2-flowered, the rachilla prolonged as a plumose bristle; glumes about 4 ram. long, narrow, tapering to an acute apex, green along the midnerve, the margins scarious, glabrous except the scabrous keel, the first 1-nerved, the second 3-nerved; lemmas about 4 mm. long, rounded on the back, 5-nerved, scabrous, scarioustipped, the apex erose, obtuse, 2-lobed, the awns of both lemmas geniculate, 5-6 mm. long, exserted, attached about the middle; palea slightly exceeding the lemma; callus and rachillajoints pilose with short hairs, the prolongation of the rachilla about one third as long as the upper floret.
Type locality; Otinapa, Durango (Palmer 342).
Distribution; Durango (Palmer 128, 342, 3550) and Jalisco (Ynez Mexia 1659).