Japan Flora: Annual; culms tufted, rather firm, stout, 40-100 cm. long, glabrous; leaf-blades 20-30 cm. long, 4-10 mm. wide, sparingly pilose, nearly flat, the sheaths whitish pilose; ligules whitish, 3-5 mm. long, ovate; panicles 10-25 cm. long, ovate, rather firm, the branches geminate, scabrous, spreading; spikelets compressed, yellowish green, narrowly ovate, 3- to 6-flowered, lustrous, 2-3 cm. long; glumes broadly lanceolate, acuminate, keeled, the lower 3- to 5-nerved, 10-12 mm. long, the upper 7- to 9-nerved, 12-15 mm. long; lemmas 14—18 mm. long, broadly lanceolate, chartaceous, folded and strongly keeled, very acute, terminated by an awn about 1 mm. long; palea 8-9 mm. long; anthers usually not exserted, 0.5 mm. long, oblong.  June-July. 

Naturalized in Honshu, Shikoku, Kyushu; very common. S. America.