Perennial, tufted from a rootstock. Culms weak, scrambling, 1–1.3 m tall, 5–7-noded. Leaf sheaths smooth or scabrid, leaf blades linear, thin, 7–20 cm × 2–7 mm, both surfaces scabrid, base contracted, apex acuminate; ligule 2–4 mm, back scabrid, apex truncate. Panicle large, effuse, delicate, ovate in outline, 27–30 cm; branches 3–5 per node, branches, branchlets, and pedicels all divaricate, slightly flexuous, capillary, scabrid or smooth; pedicels 1.5–3 mm. Spikelets hyaline, 1.5–1.8 mm, green or greenish purple at maturity; glumes finally deciduous from pedicel, narrowly ovate, subequal, scarcely keeled, lower glume scabrid on vein below apex, upper glume smooth, apex acute; callus glabrous or almost so; lemma 3/4 spikelet length or more, midvein terminating at middle of back, awnless, apex narrowly truncate; palea ca. 0.5 mm. Anthers 0.5–0.7 mm. Fl. and fr. Jul–Sep.