Very slender, glabrous, freely branching perennial without distinct rhizomes; culms smooth, 20-70 cm. long, erect from a decumbent base, the nodes glabrous; leaf-blades thin, flat, broadly lanceolate to narrowly ovate, glabrous, 3-7 cm. long, 7-10 mm. wide, abruptly acuminate, acute to rounded at the oblique base; sheaths 2-4 cm. long, the uppermost longest; ligules very short; inflorescence long-exserted; racemes 3 to 6, very slender, spreading to deflexed, sessile, 4-6 cm. long, many-jointed, green, the joints 3-5 mm. long, scaberulous, with a ring of very short hairs at apex; spikelets geminate, 3 mm. long, alike, broadly lanceolate, acute, with a of short hairs at base, the pedicels 1-1.5 mm. and 2.5-3 long, respectively; first glume scaberulous, with a broad, shallow groove between the 2 slender keels above, the second as long, 3-nerved, rather acute; fertile lemma about 2 mm. long, with a delicate, minutely scaberulous, flexuous awn 6-8 mm. long; anthers 2. Aug.-Oct. Woods in low mountains.
Hokkaido, Honshu, Shikoku, Kyushu; common. s. Korea and China.
Var. boreale (Ohwi) Ohwi Culm-nodes short-pubescent.----- Shaded places in mountains; Hokkaido, Honshu (centr. distr. and northw.).