Annual. Culms tufted, erect, soft, 15–90 cm tall, 2–4-noded. Leaf sheaths glabrous, usually longer than internodes; leaf blades 5–20 cm, 3–10 mm wide, grayish green, scabrid or abaxial surface smooth, apex acute; ligule 3–8 mm. Inflorescence 10–30 cm; racemes erect or narrowly ascending, 1–4 cm. Spikelets orbicular-cuneate in outline, flattened, 2.5–3 mm, gray-green, floret 1(–2); glumes glabrous or hispid, slightly inflated, laterally compressed, veins prominent, linked by oblique transverse veinlets; lemma scaberulous, apex cuspidate-aristate. Anthers 0.4–1 mm. Caryopsis oblong, ca. 1.5 mm, with a tuft of hairs at apex. Fl. and fr. Apr–Oct. 2n = 14.

Riversides, swampy meadows, damp places; below 3700 m. Anhui, Fujian, Gansu, Guizhou, Hebei, Heilongjiang, Hubei, Jiangsu, Jilin, Liaoning, Nei Mongol, Qinghai, Shandong, Sichuan, Xizang, Yunnan, Zhejiang [Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Russia; Europe, North America].