Japan Flora: Glabrous, soft, somewhat fleshy annual; stems 20-40 cm. long; radical leaves long-petioled, the blade cordate, reniform-cordate, or rarely ovate-cordate, 5-10 cm. long and as wide, very ab­ruptly attenuate to an obtuse apex, the cauline leaf similar, but short-petioled; inflorescence terminal, rather many-flowered, finally elongate and 5-15 cm. long in fruit; flowers on obliquely ascending pedicels, 2.5-3 cm. across, purplish blue; perianth-segmen技 elliptic, about 15 mm. long; anthers versa­tile, the larger one single, about 4 mm. long, light blue, the others about 3 mm. long and yellowish; style curved; capsules narrowly ovoid-conical, about 10 mm. long. Sept-Oct. Common in ponds and ditches.

Hokkaido, Honshu, Shikoku, Kyushu. Korea, Ussuri, and China.