Culms 15–38 cm tall, 0.4–0.8 mm thick. Basal ligules 1–2 mm, acute; upper ligules to 2.5 mm; blades filiform, about 0.3 mm in diameter. Panicles 6–10 cm, loosely contracted; branches ascending to appressed. Glumes 3–4.5 mm; florets 2.8–4.2 mm; calluses0.3–0.7 mm; lemmas with 0.1–0.4 mm lobes; awns 10–14 mm, scabridulous, not hairy, weakly once- or twice-geniculate; anthers0.5–1.5 mm, penicillate. Caryopses 1.5–2.3 mm. 2n = 22.
Ptliagrostis kingii grows along damp streambanks and wet meadows of the Sierra Nevada, at elevations from 2700–3500 m. It differs from most species in the genus in its scabridulous, rather than plumose, awns and short lemma lobes.