Plants perennial; forming dense, stiff clumps, not rhizomatous or stoloniferous. Culms 6–30 cm, decumbent to erect. Leaves forming a dense, bristly basal tuft; ligules 0.7–2.3 mm, dorsal surfaces scabridulous, apices truncate to obtuse, often erose, sometimes lacerate or ciliolate; blades 2–5 cm long, less than 1 mm wide, soon becoming tightly inrolled and rigid. Panicles 2–8 cm long, 0.2–0.6 cm wide, narrowly cylindric, spikelike, dense, occasionally interrupted near the base, the base often enclosed by the upper sheaths; branches to 2 cm, scabrous, strongly appressed, hidden by the spikelets; pedicels 0.5–7 mm. Spikeletslanceolate to narrowly ovate, greenish to purplish. Glumes 1.8–4 mm, often 3-veined, midveins scabrous to smooth, acute to acuminate; calluses glabrous; lemmas 1.5–2.5 mm, 5-veined, veins obscure or prominent distally, extending as teeth to 0.2 mm, unawned or awned from above midlength, awns to 1.2 mm, usually scarcely exceeding the lemma apices, straight; paleas to 0.3 mm, thin; anthers 3, 0.7–2 mm. Caryopses 1–1.5 mm; endosperm liquid. 2n = 42.

Agrostis blasdalei is a xerophytic species that is known only from Mendocino to Santa Cruz counties, California, where it grows on coastal cliffs and dunes and in shrublands. It hybridizes with A. densiflora.