Culms 40–100 cm; lower nodes glabrous. Lower sheaths glabrous or puberulent, not ciliate; ligules of lower leaves 0.5–1 mm, thickly membranous, rounded; ligules of upper leaves to 3 mm, scarious, acute; blades 0.5–1 mm wide. Panicles 10–30 cm. Glumes subequal, 30–60 mm; florets 15–18 mm; calluses 4–5 mm; lemmas evenly pubescent, hairs shorter than 1 mm; awns120–220 mm, first 2 segments hairy, hairs mostly 0.2–1 mm, terminal segment flexible, pilose, hairs 1–3 mm. 2n = 44.

Hesperostipa neomexicana grows in grassland, oak, and pinyon pine associations, from 800–2400 m, usually in well-drained, rocky areas in the southwestern United States and adjacent Mexico. It is similar to H. comata subsp. comata, differing in its longer awn hairs and shorter ligules.