Japan Flora: Glabrous green perennial; stems several, tufted, 15-30 cm. long; leaves deeply cordate, rounded, mucronate, 15-30 mm. in diameter; radical leaves long-petiolate, the cauline sessile and clasping; flowers 2-2.5 cm. across; petals ovate, fimbriate, distinctly clawed at base; anthers about 1.5 mm. long, the filaments spreading in anthesis.  Aug.-Sept. Wet places in mountains.

Honshu (centr. distr. and westw.), Shikoku, Kyu­shu.

var. japonica (Nakai) Ohwi. Plants larger than in the preceding with leaves to 6 cm. across, the flowers 3-3.5 cm. across, the petals about 15 mm. long, the staminodes about 5 mm. long. Aug.-Sept. Wet places in mountains; Hon­shu (Mount Togakushi and Mount Ontake in Shinano).