Japan Flora: Perennial herb, with short rhizomes and numerous small bulbils in leaf-axils; leaves long- petiolate, blades sagittate, rarely subsagittate and rounded at base, the terminal lobe linear or broadly lanceolate, 7-20 cm. long, 5- to 7-nerved, acuminate with an obtuse tip, the basal lobes usually a little shorter than the terminal; scapes 30-80 cm. long; inflorescence racemose, the pistillate flowers several, on the lower part, pedicelled, the staminate flowers rather long- pedicelled; sepals ovate to narrowly so, obtuse, 4-7 mm. long; anthers yellow; achenes obovate, inclusive of the broad wing, rostrate, 3-3.5 mm. long. July-Oct. Wet places, ponds, riverbanks.

Hokkaido, Honshu, Shikoku, Kyushu.