Plants cespitose, not stoloniferous. Culms 10-75 cm, erect. Sheaths closed for less than 1/3 of their length, smooth to scabridulous; ligules 3-7 mm, acute, usually lacerate; blades mostly 4-20 cm long, 1-4.5 mm wide, smooth to scabridulous, margins cartilaginous and whitish. Panicles (4)6-11(13) cm long, mostly 0.8-2.5 cm wide, erect or ascending; branches 10-25 mm, usually straight, stiff, mostly with 1-2 spikelets. Spikelets 12-16 mm, with 3-6 florets; rachilla internodes mostly 1.5-2.5 mm, hairs 0.2-1.5 mm. Glumes thin, acute; lower glumes 9-13 mm, 3-veined; upper glumes 9-14 mm, 3-5-veined; calluses bearded, hairs usually shorter than 1 mm; lemmas 10-12 mm, awned, awns 10-17 mm, flattened below the bend; paleas 6-8.75 mm; anthers 2.5-5 mm. 2n = 14.
Avenula hookeri grows on mesic to dry, open prairie slopes, hillsides,
forest openings, and meadows, in montane to subalpine zones, from Alaska
and northern Canada to New Mexico.