Japan Flora: Small tree, the young branchlets sometimes pubescent; leaves obovate or ovate, 3-5 cm. long, 2-3 cm. wide, short-acuminate, pubescent on upper side and on nerves beneath, doubly acute-toothed, the petioles 8-10 mm. long; flowers 1-3, in sessile umbels, white to rose, on glabrous to thinly pubescent pedicels 1-2.5 cm. long; calyx­tube usually glabrous, 5-6 mm. long, about twice as long as the lobes; petals about 10 mm. long, retuse. Apr.-June. Mountains.

Honshu (centr. distr. and northw.).

f. yamadei (Makino) Ohwi. Young leaves, calyx, and pedicels green.

var. tomentosa Koidz. Leaves larger, broader; calyx-lobes clearly serrulate.  Low mountains; Honshu (w. Kanto Distr.).

var. kinkiensis (Koidz.) Ohwi. Differs from the typical phase in the longer calyx-tube and slightly larger caudate leaves. Moun­tains; Honshu (w. part of centr. distr. and westw.).

var. bukosanensis (Honda) Hara. Leaves larger, broadly obovate, 5-8 cm. long, 3-5 cm. wide, glabrescent on both sides. Mountains; Honshu (Mount Buko in Musashi).