Japan Flora: Much-branched shrub with slender, green, spreading, glabrous branches; leaves membranous, ovate or narrowly so, 3—7 cm. long, 2-3.5 cm. wide, long-acuminate, incised duplicate-toothed, vivid green, paler beneath, nearly glabrous; flowers 2.5-5 cm. across; calyx glabrous, the tube short, the segments broadly ovate to elliptic, spreading, denticulate; petals ovate-orbicular, spreading; achenes 4-5 mm. long. Apr.-May. Common in moun­tains.

Hokkaido, Honshu, Shikoku, Kyushu. Several cultivars are grown