Japan Flora: Plant loosely tufted; culms 30-70 cm. long, acutely 3-angled, with 1 node; leaf-blades flat, rather stiff, deep green, 3-5 mm. wide, the basal sheaths bladeless, brownish red; spikes 3 or 4, 1.5-3 cm. long, all but the lowest one approximate or nearly fastigiate, the terminal staminate, linear, pale to light tawny, usually overtopped by the lower pistillate ones, 1.5-3 cm. long, erect, densely flowered, cylindric, peduncled, the bracts leaflike, the lower longer than the inflorescence, long-shea thing; pistillate scdes elliptic, pale, with a broad green 3-nerved midrib projecting as a long awn; perigynia as long as or slightly shorter than the awns of the scales, about 3 mm. long, spreading, obovoid-globose, much inflated, thick-membranous, obsoletely 3-angled, light green, brownish when dried, abrupdy short-beaked, with a hyaline 2-toothed tip; stigmas 3, short. Wet sunny grassy places or open woods.
Hokkaido (sw. distr.), Honshu, Shikoku, Kyushu; rather rare. Korea, China, Formosa to Australia.