Japan Flora: Tree with rather thick branches; leaves 20-40 cm. long, petiolate, the leaflets 5-13, membranous, narrowly ovate or ovate-oblong, 2-10 cm. long, 3-5 cm. wide, caudate-acuminate, rounded at base, usually ciliate while young or slightly pubescent be­neath near base, deep green, glaucous beneath; cymes rather large, 5-7 cm. across, pnberulons; flowers on short pedicels; sepals ovate-triangular, about 1 mm. long; petals narrowly oblong, pubescent inside, about 4 mm. long; fruit nearly glo­bose, about 1 cm. across. July. Woods in mountains.

Hokkaido, Honshu, Shikoku, Kyushu. Korea, n. China, Manchuria, Ussuri, and Amur. Variable.

var. sachalinense F. Schmidt. Bark thin; leaflets slightly broader, nearly destitute of marginal hairs; cymes nearly glabrous. Hokkaido,  Honshu.

var. japonicum (Maxim.) Ohwi. Leaflets 1-15, rather smaller, spreading-pubescent beneath especially on nerves; cymes puberulous. Honshu, Shikoku, Kyushu.

var. lavallei (Dode) Sprague.  thicker, corky bark; leaflets broadly cuneate at base. Hok­kaido, Honshu.

Korea Flora: Deciduous tree. Height up to 10m. Bark light gray, deeply fissured with developed cork, inner bark yellow. Branches thick and spread in all directions. Winter buds infrapetiolar, semicircular, with rounded tips and 2 bud scales. pseudoterminal buds paired, larger than lateral buds, 2-4mm long. Leaf scars U-shaped and wide. Leaves opposite, odd-pinnate compound leaves. 5-13 leaflets, ovate, with tail-like tips and rounded bases. leaf size 5-10cm × 3-5cm. Upper surface glossy, underside white with some or many hairs on the lower part of the veins. Flowers dioecious. panicles inflorescence slightly hairy, 5-7cm in diameter. short pedicels, 5-8 petals. sepals short, petals 4mm long with hairs on the inside along with the base of the filaments. Ovary 5 chambers. Fruit round and black, many persisting through winter, containing 5 seeds.

Sporophyte chromosome number: 28, 78 (ca. 80, 66).

Flowering June

Fruiting  Late September

Distribution: Northeastern China, northern-central China, southern Far East Russia, throughout Japan; North and South Hamgyong Provinces, North and South Pyongan Provinces, Gangwon Province, Gyeonggi Province, and Ulleung Island in Korea.

Ecological characteristics: Light-demanding, weak shade tolerance, requires much light when young. Grows well in moist, fertile soils, often found in valleys and lower mountain slopes. Roots grow deep, and growth is rapid when young.

Taxonomic notes: Previously, varieties with densely pubescent leaflet undersides (P. molle Nakai), those with 3-5 leaflets and hairs on the underside veins (P. insulare Nakai), and those with ovate-elliptical leaflets, less prominent cork on the bark, and fewer hairs on leaflet margins (P. sachalinense (F. Schmidt) Sarg.) were recognized as separate species. However, in recent studies by Ma et al. (2006), these have been treated as synonyms of the main species.