Japan Flora: Annual; culms tufted, soft, 20-70 cm. long; leaves soft, 2-6 mm. wide; corymbs large, compound, 5-20 cm. long, with 5-7 oblique, spreading to ascending rays to 20 cm. long, the bracts 3-5, the lowest one longer than the in­florescence; spikelets linear, slightly compressed, 5-10 mm. long, 1.5 mm. wide, dark reddish purple; scales broadly ellip­tic, 1.2 mm. long, rounded-truncate, entire; achenes slightly shorter than the scale, obovate, 3-angled, dark brown; stigmas 3.    Aug.-Oct. Wet places; Hokkaido, Honshu, Shikoku, Kyushu; common. Korea, China, Northeast China, Ussuri, and Dahuria.