Ohwi 1985 Flora of Japan

Tree with glabrous branches; leaves chartaceous, orbicular, 6-10 cm. wide, palmately 9- to ll-lobed, shallowly so, somewhat cordate at base, rather prominently duplicate-serrate, white- pubescent on both sides while young, soon glabrous except for an axillary tuft beneath, the lobes ovate, acuminate, the petioles 3-8 cm. long, rather slender, glabrous; inflorescence a more than 10-flowered compound corymb, the peduncles 4-6 cm. long, glabrous; flowers pale yellow, 6-8 mm. across; sepals broadly lanceolate, about 4 mm. long; ovary with a few long hairs; samaras glabrous, the wings ascending, about 2 cm. long including the nutlets.

May-June.

Mountains; Honshu, Shikoku.