Japan Flora: Rhizomes firm, creeping, the internodes short; stems 40-70 cm. long, terete, rather firm, about 2 mm. across at base; leaves linear, grasslike, rather flat, whitish green, shorter than the stem, the auricles small; flowers solitary, in a terminal compound cyme; bracts leafy, longer or shorter than the in­florescence; perianth-segments ovate-oblong, 2.2 mm. long, ob­tuse, dark brown-purple on back, red-brown on both sides; stamens 6S 2/3 as long as the perianth-segments, the anthers nearly as long as the filaments; capsule ellipsoidal, brownish, lustrous; seeds ellipsoidal.  Wet or swampy places.

Hok­kaido, Honshu, Shikoku, Kyushu. n. China, Korea, Ussuri, Amur, and Sakhalin.