Korea Flora: Trees up to 14m. Bark light grayish brown. Winter buds lanceolate, acuminate, densely yellow pubescent scales 2, terminal buds larger than lateral buds (6-10mm long). Branchlets yellowish or redish, hiary. Leaf scars V form. Leaves opposite and deciduous, suborbicular, base cordate, 5(7)-lobed, 8-14cm × 8- 13cm, margin coarsely serrate, middle lobes not serrate apically, adaxially glabrescent, abaxially densely yellowish tomentose along the vein, petiole 3-12cm, slightly pubescent and reddish, Inflorescence terminal, erect, racemose-paniculate, pubescent, andromonoecious; peduncles 3-5 cm, Pedicel 4-6 mm, pubescent. Sepals 4, outside pubescent. Petals 5, yellow. Stamens 8, or 7-10, glabrous, longer than petals, Ovary densely pubescent. wing including nutlet 15mm, puberulent;
2n= 26. Flowering late May – late June Fruting mid Sept- mid Oct Distribution Northeastern China, far Eastern Russia and southern Kurils, Japan (Hokkaido, Honshu); Korea [North, Central (Baekdudaegan)]
Japan Flora: Tree, the branches yellowish puberulent; leaves orbicular and 5-angled, 8-13 cm. long, 8-15 cm. wide, cordate at base, often whitish and with dull yellowish pubescence beneath, palmately 5(-7)-lobed on outer third, the lobes ovate-triangular, acuminate, sharply serrate and incised, the petioles 6-12 cm. long; inflorescence an erect raceme, 10-15 cm. long inclusive of the peduncles 3-5 cm. long, densely many-flowered, with pale brown soft hairs, the pedicels about 10 mm. long; flowers yellowish; sepals broadly lanceolate, about 1 mm. long; petals narrowly obi a nee- olate, about 2 mm. long; samaras loosely short-pubescent or glabrous, ascending, 1.5-2 cm. long. July-Aug. Highmountains; Hokkaido, Honshu (centr. distr. and northw.), Shikoku. Sakhalin, Korea, Manchuria, e. Siberia, and Kuriles.
f. pilosum Nakai. Usuge-ogarabana. Leaves less prominently pubescent beneath. Occurs with the species
China Flora: Deciduous tree, up to 10(-15) meters tall. Young branches purple, yellow pubescent, old branches brown, nearly glabrous. Winter buds short conical, dark purple, yellow pubescent. Leaves nearly round, 10-12 cm long, 7-9 cm wide, 5(7) deeply lobed, cordate at base, lobes broadly ovate, pointed at apex, coarsely serrulate and doubly serrate, glabrous above, densely yellowish hairs below, densely hairy above veins, 5 basal veins; petiole 5-10 cm long. Raceme terminal, up to 10 cm long, erect, pubescent. Dioecious; sepals yellowish green, lanceolate, 2 mm long, slightly pubescent; petals white, slightly yellowish, oblanceolate, 3 mm long; stamens glabrous; disk slightly lobed; located outside the stamens, ovary densely pubescent. The samaras are light red when young and yellow-brown when ripe. The nutlets are slightly hairy, with a core diameter of 6 mm and a wing length of 1.5-2 cm, with the two wings at right angles. The flowering period is May and the fruiting period is September.
It is produced in Heilongjiang, Jilin and Liaoning, and grows in sparse forests at an altitude of 500-1500 meters. It is distributed in eastern Siberia, Russia, North Korea and Japan. [translated from Higher Plants of China]
Russia Flora: Tree 5-7 (14) m tall, with characteristic flaking yellowish-gray bark, often taking the form of a large shrub. Terminal buds lanceolate, 6-8 mm long, dark cherry-colored; bases and edges of scales finely pubescent. Bud stalks about 1-1.5 mm long or buds almost sessile. Shoots dark cherry-colored, glabrous, finely pubescent at nodes. Leaves 5-lobed, with middle lobe larger than lateral ones, sometimes almost 3-lobed, generally rounded-ovate in outline, up to 15 cm long, and larger on replacement shoots, base more or less deeply cordate, sparsely soft-hairy above, densely soft-hairy below (especially along veins), sometimes by autumn pubescence remaining only on veins; leaf blade lobes gradually drawn into sharp tips, coarsely and unevenly doubly toothed. Petioles 5-9.5 cm long, always shorter than leaf blade, soft-hairy. Flowers up to 3 mm in diameter, yellow, arranged in long dense many-flowered raceme; petals 2-3 times longer than sepals; stamens about 3 mm long, twice as long as petals; ovaries densely hairy. Samaras 1.5 (2) cm long, diverging at right or not very acute angle. 2n=26 (Gurzenkov, 1973). (Table XIX).
Distribution: North Sakhalin, Upper Zeya, Lower Zeya, Bureya, Amgun, Ussuri, South Sakhalin, South Kuril (Fig. 65). - In coniferous and mixed forests of various types, in the south predominantly in the dark coniferous forest zone. Flowering in June. Honey plant, ornamental, but almost unused in landscaping in the Soviet Far East.
General distribution: Japanese-Chinese (North and Northeast China, Korean Peninsula, Japan - islands of Hokkaido and Honshu). - Described from Khabarovsk: "In mountains of Ukurundu, at Ulban Bay, E. Trautvetter, 1844" (type - LE).