Ohwi 1985 Flora of Japan

Large dioecious shrub with glabr이is branches; leaves ovate or broadly so, undivided or shallowly 3-fid near the base, 4-7 cm. long, 3-4(-7) cm. wide, long-acuminate, shallowly cordate at base, rather irregularly toothed, short rusty brown pubescent while young, paler beneath, the petioles glabrous, 1-2 cm. long; inflorescence a glabrous raceme 3- 5 cm. long, about 10-flowered, the peduncles 1-1.5 cm. long, the pedicels slender, 4-10 mm. long; flowers yellowish green, about 8 mm. across; sepals narrowly oblong, ascending, about 4 mm. long; petals spathulate-obovate, slightly longer than the sepals; stamens about 8, about one-half as long as the sepals; samaras glabrous, horizontally spreading to ascending, about 2 cm. long.

May.

Woods and thickets in low mountains; Honshu, Shikoku, Kyushu; common.