Japan Flora: Rhizomes 7-10 mm. across, few-leaved in upper part; leaflets rather thick, oblong, ovate- elEptic, or rhombic-elliptic, sessile, 4-8 cm. long, 2-5 cm. wide, obtuse, obtusely toothed, or nearly entire, sessile; scapes terete, 20-40 cm. long, the bracts broadly ovate, 3-8 mm. long, the pedicels 1-2.5 cm. long; flowers 1-1,5 cm, across; calyx short, the lobes elliptic; capsules 5-7 mm. across; seeds 2.5-3 mm. across. Apr.-Aug. Wet boggy places and margins of lakes and ponds;

Hokkaido, Honshu, Kyushu; rather common.