Japan Flora: Slender annual; culms 40-100 cm. long from a decumbent, branched, rooting base, glabrous; leaf-blades thin, flat, lanceolate, 4-10 cm. long, 8-15 mm. wide, short-acuminate, obliquely cuneate at base; ligules truncate, about 0.5 mm. long, puberulent on back; sheaths pubescent at least on outer margin above, d'orter than the leaf-blades and internodes of culms; inflorescence at length exserted; racemes 1-3, nearly erect to ascending, straight, green, 5-7 cm. long, the rachis joints rather thick, 3-angled, 3.5-5 mm. long, thickened above, short-pilose on the angles; pedicels about 2/3 as long as the spikelets; spikelets green, 4-8 mm. long, the pedicelled ones somewhat flattened laterally, the sessile ones with a shallow groove on the face between the 2 ciliate keels; awn long-exserted, to 15 mm. long;Sept.-Oct. Woods in lowlands and in low mountains.
Hokkaido, Honshu, Shikoku, Kyushu; common. Korea, China, Ryukyus, Formosa, Malaysia, India, and the Caucasus.
Russia Flora: Plant 20—50 cm tall. Stems thin, geniculate, semi-prostrate or ascending, often branched at lower nodes, rooting. Sheaths glabrous, sometimes with hairs along margin; leaf blades 8—15 mm wide, lanceolate, petiolately narrowed toward base, scattered appressed-hairy beneath (and often above); ligule of upper leaves 0.5—1 mm long, long-ciliate. Inflorescence 2—8 cm long, of (1) 2—5 almost digitately arranged spike-like branches, breaking into segments 2.5—4 mm long at fruiting in upper part. Spikelets 5—6 mm long, arranged in pairs, with 2 flowers, where upper — bisexual and fertile, and lower — sterile. Glumes equal in length to spikelet, acuminate, with prominent veins (upper — keeled). Lower lemma (of fertile flower) bidentate at apex, with twisted thick awn up to 12 (18) mm long. Anthers (0.3) 0.5—1 (2) mm long. 2n=40 (Sokolovskaya, Probatova, 1977a). (Plate XXVI).
Ussuri (south). (Fig. 161). — On wet meadows, forest edges, along paths, sometimes as weed and along roads. VIII—X. — General distribution: Japanese-Chinese, introduced to other countries. — Described from Korean Peninsula.