Japan Flora: Rhizomes creeping; stem terete, slightly thickened, 30-60 cm. long, 2- or 3-leaved; leaves all cauline, shorter than the in­florescence, terete, unitubulose, perfectly septate; inflorescence a relatively dense terminal cyme of rather numerous, 3- to 10-flowered, small heads, the lowest bract leaflike, exceeding the inflorescence; flowers sessile, 3-4 mm. long when mature; perianth-segments broadly lanceolate, acute, greenish, the inner slightly longer than the outer; stamens 6, shorter than the perianth-segments, the anthers ovoid, much shorter than the filaments; capsules ellipsoidal, 3-angled, rather obtuse, slightly longer tlian the perianth, rather thick; seeds obovoid, 0.5 mm. long. Aug.-Oct. Wet or marshy places.

Hokkaido, Honshu, Kyushu. Kuriles, Korea, Ryukyus, and n. China.