Japan Flora: Young branchlets usually stellate-pilose; stipules lanceolate to narrowly ovate, toothed; leaves 15-30 cm. long, minutely puberulent on petioles and axis, the pinnae 15-23, membranous, lanceolate or broadly so, 4-10 cm. long, 8-30 mm. wide, acuminate, acutely duplicate-toothed, more or less stellate-pilose beneath; panicles 10-20 cm. long, densely many­ flowered, stellate-pilose, becoming glabrous; flowers white, 7-8 mm. across; stamens longer than the petals; styles about 2.5 mm. long; fruit 4-6 mm. long, pubescent. July-Aug.

Hokkaido, Honshu (centr. and n. distr., rare).

f. incerta (C. K. Schn.) Kitag. Stellate hairs on under­ side of leaves deciduous at anthesis. The typical phase occurs in nw. Asia.

 

Korea Flora: Deciduous shrub, 2m tall. Roots spread like rhizomes, with many stems arising from a single point; glabrous or with stellate hairs. Winter buds ovoid, apex acute, with 5-8 basal scales; terminal buds similar to lateral buds (5-9mm long); leaf scars triangular. Leaves alternate, pinnate compound leaves with 13-23 leaflets, 6-8cm × 1.5-2.5cm; apex elongated-acuminate, base rounded, doubly serrate margins; upper surface glabrous, lower surface with stellate hairs. Petioles 20-27cm long, pubescent. Flowers in large panicles at branch tips. Flowers 5-6mm in diameter, white; calyx lobes and petals each 5, stamens 40-50, longer than petals. Ovaries 5, glabrous, free. Fruits follicles, 5, 6mm long, densely covered with stellate hairs.

Flowering: June-July.
Fruiting: Mid-September to mid-October.
Distribution: Northeastern China, Far East Russia, Hokkaido to central Honshu (Japan); South and Hamgyeongbukdo s, South and North Pyeongan s to Gangwon along the Baekdudaegan mountain range (Korea).
Ecological note: Grows primarily in mountain valleys near streams.
Taxonomic remarks: Var. stellipila Maxim. with leaf abaxially stellate and inflorescence and fruite stellate (stipitate-glanfular or stipitate-stellate), is known to differ from var. sorbifolia, but there’s not much difference between them.