Japan Flora: Culms 15-50 cm. long, soft, about 1 mm. thick, in dense tnfts, acutely angled, glabrous; leaf-blades 2-3 mm. wide, flat, soft, thin; spike solitary, terminal, 7-10 mm. long, androgynous, ovate to oblong, the staminate 2-3 mm. long, shorter than the pistillate; pistillate scales oblong-lanceolate, acute, pale fer­rugineous; perigynia longer than the scales, somewhat re­flexed, ovate-lanceolate, inflated, 3-angled, membranous, pale grcen, faintly nerved, gradually long-beaked, emarginate; stigmas 3. Wet places in mountains.

Hokkaido, Honshu (Mount Kirigamine in Shinano Prov.); rare. Sakhalin, Korea, Amur, and Ussuri.