Korea Flora: Deciduous shrub or small tree. Winter buds and branchlets: Branch tips with one terminal bud, broadly ovate or conical, pointed, 4-6mm long, with 2-4 opposite bud scales. Scales dark black with sparse or almost no hair. Lateral buds opposite, smaller than terminal bud. Branchlets grayish-brown, often with fine hair when young. Leaf scars semi-circular or crescent-shaped. Leaves opposite (occasionally sub-opposite), odd-pinnate compound. 5-7(9) leaflets, ovate or oblong-ovate, acuminate apex, cuneate or rounded base, size 5-10cm × 1.5-3.5cm. Upper surface hairless, green or reddish-green; lower surface with white hair on midrib. Margins with small teeth or almost entire (some populations in Mt. Baekun, Jirisan, or Deogyusan have very distinct small teeth). Short leaflet stalks, petioles grooved on upper surface, 6-11cm long. Flowers in panicles at branch tips or leaf axils, 6-12cm long. Petals linear, 5-6mm; calyx very small and vestigial, equal in length to stamens. 2 stamens, female flowers with rudimentary small stamens. Fruits linear-lanceolate or oblanceolate samara, 2cm long including wing.

Flowering May to early June.

Fruiting September.

Distribution: Honshu, Shikoku, Kyushu in Japan; Hwanghaedo, south of Gyeonggido (very limited areas in Gangwon-do), Korea.

Ecological characteristics: Grows well in moist areas with sufficient light, but also tolerates dry conditions, slopes, and rock faces.

Taxonomic notes: F. sieboldiana var. quadrijuga (Nakai) T. B. Lee is an invalidly published name. Some individuals from Mt. Baekun, along with some from Jirisan and Deogyusan, have distinctly developed teeth on leaflets, but this characteristic is not considered significant enough to recognize as a separate variety.

 

Japan Flora: Deciduous tree; buds closed, the scales gray-puberulent to nearly glabrous outside; branchlets slender, gray-brown, spreading-pubcrulent while young; leaves 5-(-7)-foliolate, 10- 15(-20) cm. long inclusive of the petioles, the petioles and rachis puberulent while young, the leaflets narrowly to broadly ovate, sometimes broadly lanceolate, 5-10(-13) cm. long, 1.5- 3.5 cm. wide, long-acuminate, glabrous or with spreading white hairs along the midrib beneath, toothed or nearly entire, subsessile; calyx minutely toothed; petals 4, 6-7 mm. long, free, linear-oblanceolate, white; samaras oblanceolate to linear-ob­lanceolate, 2.5-3 cm. long, about 5 mm. wide. Apr.-May. Mountains and hills.

Honshu, Shikoku, Kyushu; common. Korea.