Ohwi 1985 Flora of Japan

Tree with glabrous branches; leaves membranous-chartaceous, thin, ovate- orbicular, 4-7 cm. wide, cordate at base, (5-) 7- to 9-lobed, sometimes to the middle, sparsely white-pubescent, soon becoming glabrous except in the axils, or with very sparse persistent pubescence on nerves beneath, the lobes lanceolate, rhombic-lanceolate, or narrowly rhombic-ovate, acuminate, incised and doubly serrate acute-toothed, the petioles slender, 2-5 cm. long, glabrous or nearly so; inflorescence corymbose, pendulous, more than 10-flowered, on slender peduncles 1.5-4 cm. long; flowers pale yellow with a red-purple hue, about 5 mm. across; sepals oblong, about 3 mm. long; ovary rather densely white-pubescent; samaras loosely pubescent or glabrous, the wings ascending, about 2 cm. long including the nutlets.

May-June.

Mountains; Honshu (Kanto Distr. and western)，Shikoku, Kyushu.