Japan Flora: Soft green annual; culms 5-25 cm. long; leaves 1-2.5 mm. wide; inflorescence capitate, globose, dense, 1-2.5 cm. across, occasionally umbelliform with 1-5 rays to 5 cm. long, the bracts leaflike; spikelets slightly flattened, lanceolate or narrowly ovate, 3-7 mxn. long, 1.5-2 mm. wide, pale green; scales 2- ranked, dense, ovate, 1.7-2 mm. long, several-nerved, hyaline, obtuse with a broad tip; achenes 2/5-1/2 as long as the scale, obovate to elliptic, lunate in cross section, obtusely angled, light brown; stigmas 2 or 3. Aug.-Oct. Honshu, Shikoku, Kyushu. Korea, China, and Northeast China.
var. spiralis Ohwi. Spike lets not flattened, obscurely angled; scales spirally arranged. Honshu, Shikoku. China.