Plants perennial; cespitose, sometimes rhizomatous. Culms 35-250 cm, decumbent, much branched above the base, becoming almost woody; upper nodes glabrous or villous, hairs to 1.5 mm; lower internodes tomentose. Ligules1-2 mm, densely ciliate; blades 2-10(16) cm long, 2-5 mm wide, flat basally, involute distally. Panicles 4-12 cm; fascicles 6-12 mm. Lateral spikelets with 2-4 florets, lower 2 florets staminate, other florets (if present) usually sterile; glumes thin, membranous, not fused at the base, lanceolate or parallel-sided, 7-veined, awned, awns exceeding the glume apices, apices 2-4-lobed, lobes acute to rounded, long-ciliate, sometimes with 1-3 excurrent veins that form additional slender awns to 1.8 mm; lower glumes with dorsal, divergent awns; upper glumes with subapical awns; anthers 3, 4-4.5 mm. Central spikelets equaling or exceeding the lateral spikelets, with 1 stipitate, bisexual floret; glumes thin, membranous, narrow, deeply cleft into few-several acuminate, ciliate lobes and slender awns; lemmas often exceeding the glumes, thin, ciliate, 2-lobed, midveins excurrent. 2n = 18, 36, 54.
Hilaria rigida grows in deserts and open juniper stands, at low elevations, from the southwestern United States to central Mexico. Although almost shrubby, it is very popular with pack horses.