Japan Flora: Rhizomes elongate, slender; culms solitary, nearly naked, 20-60 cm. long; leaves flaccid, short, often bladeless, 1-6 cm. long; corymbs  compound or simple, to 15 cm. across, with many spreading slender rays, the bracts 1 or 2, leaflike, longer or shorter than the inflorescence; spikelets digitate in groups of 4 or 5, linear, flat, 5-15 mm. long, 1.5-2 mm. wide, sanguineous; scales oblong to narrowly so, about 1.5 mm. long, emarginate and mucronulate with the green midrib ending as an erect slightly excurrent mucro; achenes 1/3 as long as the scale, white, 3-angled, elliptic; stigmas 3. Aug.-Oct Swampy places and rice paddies.

Honshu, Shikoku, Kyushu. Ryukyus, Formosa, China, Indochina, India, Malaysia, and Australia.