Plants perennial; cespitose, not rhizomatous, not stoloniferous. Culms 40–80 cm, geniculate and decumbent at the base, sometimes rooting at the lower nodes, with 3–6 nodes. Leaves mostly cauline; basal leaves withered by anthesis; cauline leaves persisting; sheaths smooth or scabridulous; ligules (0.9)2.7–5 mm, dorsal surfaces scabrous, apices truncate to acute, erose to lacerate; blades 15–20 cm long, 3–5 mm wide, flat. Panicles 10–25 cm long, 3.5–11 cm wide, ovate, open and diffuse, bases usually exserted, rarely enclosed in the upper sheaths, lowest node with (1)2–6 branches; branches scabridulous, flexuous, spreading, spikelets usually only on the distal 1/2, lower branches 3–10 cm; pedicels 1.2–9.4 mm. Spikeletsovate to lanceolate, green, not or slightly tinged with purple. Glumes unequal, 2.3–3.5 mm, 1(3)-veined, veins scabridulous, acute to acuminate; callus hairs to 0.3 mm, abundant; lemmas 2.5–3 mm, usually smooth, sometimes scabridulous, translucent to opaque, 5-veined, veins prominent distally or obscure, apices acute to obtuse, lateral veins extending as 4 teeth to 0.5 mm, awned from the lower 1/3, awns 4–6 mm, geniculate; paleas absent or minute; anthers 3, 1–1.3 mm. Caryopses 1.2–1.6 mm; endosperm liquid. 2n = 28.

Agrostis howellii is a rare Washington and Oregon endemic, growing in shady woodlands and at the base of cliffs.