Trisetum tonduzii Hitchc.

Trisetum tonduzii Hitchcock, sp. nov
Perennial, with creeping rhizomes; culms erect, cespitose, glabrous, 2-noded or 3-noded near the base, 30-40 cm. tall, sometimes taller; sheaths glabrous; ligule truncate or rounded, dentate, about 1 mm. long, the margin of the sheath on one side extending upward as an auricle as long as the ligule; blades mostly basal, erect, rather stiff, glabrous, loosely involute, ending in a slender point, 5-15 cm. long, 2-3 mm. wide; panicle ovate-pyramidal, open, purplish, 5-15 cm. long, sometimes nearly as wide, the axis glabrous, the branches slender, verticillate, spreading, glabrous, naked below, the verticils mostly 2-3 cm. apart, the branchlets short and somewhat appressed along the upper part of the branches, the shorter pedicels 1-2 mm. long; spikelets 2-flowered, 4—5 mm. long; the rachilla villous, the hairs at the summit as much as 2 mm. long, the callus-hairs also about 2 mm. long; glumes rather broad, equal in length, nearly equal in width, glabrous even on the keel, acute, about 4 mm. long; lemmas scaberulous, 4-4.5 mm. long, the neres excurrent as 4 short slender teeth; awn attached a little above the middle, very slightly scabrous, curved or loosely spiral at base and sharply spreading horizontally, 5-8 mm. long.
Planta perennis, rhizomata; culmi erecti, glabri, 30-40 cm. alti; vaginae glabrae; ligula truncata, dentata, 1 mm. longa; laminae glabrae, plerumque paullum involutae, 2-3 mm. latae, apice attenuatae; panicula pyramidalis, patens, 5-15 cm. longa, ramis verticillatis, patulis, glabris, inferne nudis; spiculae 2-florae, 4-5 mm. longae, pilis rachiUae et calli 2 mm. longis; glumae equales, glabrae, acutae, 4 mm. longae; lemmata scaberula, 4-4.5 mm. longa, apice quadriseta, paullum supra medium aristata, arista geniculata, inferne laxe torta, superne patula, 5-S mm. longa.
Type collected in pastures on Mount PoSs, Costa Rica, altitude 2460 meters, November 1896, A. Tonduz, Herb. Inst. Phys.-geogr. Costa Rica no. 10749 (U. S. Nat. Herb. no. 358711).
Distribution: Open grassland, high mountains of Costa Rica.