Japan Flora: Rhi­zomes long-creeping; culms 40-50 cm. long, glabrous; leaf­blades flat, fresh-green, soft, 4-7 mm. wide, the basal sheaths pale, partially dark reddish purple; spikes 3 or 4, erect, the upper 1 or 2 staminate, linear, 3-4 cm. long, long-peduncled, the others pistillate, approximate, short-cylindric, 1.5-3 cm. long, the lower ones short-peduncled, the bracts leaflike, nearly sheathless; pistillate scales ovate, acute, pale; perigynia longer than the scales, about 6 nun. long, spreading, ovoid-oval, in­flated, obsoletely 3-angled, light green, glabrous, many-nerved, the beak short, erect, with 2-toothed hyaline tip; stigmas 3. May-June. Swampy places in hills and low mountains.

Hon­shu (Shimotsuke Prov.); rare.