Culms 12–110 cm; lower nodes glabrous or pubescent. Lower sheaths glabrous or pubescent, not ciliate; ligules of lower leaves 1–6.5 mm, scarious, usually acute, sometimes trun-cate, often lacerate; ligules of upper leaves to 7 mm; blades 0.5–4 mm wide, usually invol-ute. Panicles 10–32 cm, contracted. Glumes 16–35 mm, 3–5-veined; lower glumes 18–35 mm; upper glumes 1–3 mm shorter; florets 7–13 mm; calluses 2–4 mm; lemmas evenly pubescent, hairs about 1 mm, white, sometimes glabrous immediately above the callus; awns 65–225 mm, first 2 segments scabrous to strigose, hairs shorter than 1 mm, terminal segment scabridulous.

Hesperostipa comata is found primarily in the cool deserts, grasslands, and pinyon-juniper forests of western North America. The two subspecies overlap geographically, but are only occasionally sympatric. Both are primarily cleistogamous.