Biorepository Data Portal

Plants cespitose, with knotty, shortly rhizomatous bases. Culms 20-80 cm; nodes often with soft, 1-2 mm hairs. Sheaths rounded, lower sheaths often strigose or pilose, upper sheaths glabrous or scabrous; ligules 0.5-1 mm, membranous, ciliate; blades 1-4 mm wide, usually involute or loosely infolded, glabrous, scabrous, or sparsely pilose, attenuate distally. Panicles 7-20(25) cm long, 0.3-0.8 cm wide; branches erect, spikelets imbricate but usually not crowded; pedicels 1-2 mm. Spikelets 8-13 mm, with 5-11 florets. Glumes glabrous, usually purple-tinged; lower glumes 3-8(10) mm, 1-3-veined; upper glumes 4-10 mm, 1-7-veined; lemmas 3.5-7 mm, usually purple-tinged, midveins pilose on the basal 1/3-1/2, rarely excurrent, lateral veins pilose to well above midlength, never excurrent; paleas 1-2 mm shorter than the lemmas, margins pubescent; anthers 1-1.5 mm. Caryopses 1.5-2.3 mm. 2n = 40.

FNA 2003, Gould 1980

Common Name: slim tridens Duration: Perennial Nativity: Native Lifeform: Graminoid General: Small perennial bunchgrass 20-50 cm tall, stout, with knotty, shortly rhizomatous bases. Vegetative: Sheaths open, rounded, upper sheaths glabrous, lower usually pilose; blades mostly 8-15 cm long, involute or occasionally flat, often glaucous; collar and ligule mostly long-hairy; ligule ciliate with fused base, 0.5-1 mm long, with membranous lateral aur Inflorescence: Contracted panicle or raceme, 6-20 cm, narrow and spikelike, spikelets rather distant, not crowded; spikelets 9-13 mm long and 5-10 flowered; glumes broadly lanceolate or ovate, very thin and hyaline, one-nerved, the second glume rarely with short lateral nerve stubs; lemmas about as long as glumes, thin, hyaline or deeply tinged with purple, apex broadly rounded, occasionally notched or mucronate. Disarticulation above the glumes. Ecology: Dry plains, rocky slopes, grasslands, and woodlands; below 5,500 ft (1676 m); flowers May-September. Distribution: s CA, s NV, AZ and UT, west to TX, KS, MO and OK; south to s MEX. Notes: Distinguished as a small perennial bunchgrass, to 50 cm tall, with a contracted, spike-like inflorescence bearing multi-flowered spikelets, each with a purple lemma, giving the spikelets horizontal purple or white stripes. Each floret is long-hairy on veins and rounded to truncate, sometimes with a notch at the apex. When mature, seeds drop off, leaving a pair of paper-like scales (glumes) that persist through the year. Var. muticus can be distinguished by its upper glumes 4-6 mm long, 1-veined. Var. elongatus is distinguished by its upper glumes being 5.5-10 mm long and 3-7 veined. Both varieties are found in the US Southwest. Ethnobotany: Used as fodder. Etymology: Tridens means three-toothed, referring to the three shortly excurrent veins on the lemmas of Tridens flavus, the type species; muticus means blunt or without a point, possibly referring to the shape of the lemmas on this species. Synonyms: Triodia mutica Editor: SBuckley 2010, FSCoburn 2014, AHazelton 2015