Japan Flora: Small green annual; culms flaccid, tufted, 5-25 cm. long; leaves usu­ally reduced to short-bladed or bladeless hyaline sheaths; corymbs simple or subcompound, rather loose, with 3-5 short rays, rarely to 10 cm. long, the bract solitary, decurrent on the culm, nearly as long as the inflorescence; spikelets digitate, in groups of 2-6, strongly flattened, light green, 5-12 mm. long, 2 mm. wide; scales spreading, broadly ovate, 1 mm. long, the keel conspicuous, more or less winglike, excurrent at apex as a recurved awn 1/5-1/4 as long as the scale; achene 1/3 as long as the scale (including the awn), broadly obovate, 3-angled, light yellow; stigmas 3.  Aug.-Oct. Wet grassy places in low grounds.

Honshu, Shikoku, Kyushu. Korea and China.