A tree 80 to 100 ft high, trunk 8 to 10 ft in girth; young shoots nearly glabrous. Leaves 8 to over 12 in. long, composed of eleven to twenty-one leaflets, which are rounded at the base, pointed at the apex, oblong, finely and evenly toothed, 21⁄2 to 4 in. long, 1 to 11⁄2 in. wide; common-stalk not winged. The stalk and leaves vary in regard to pubescence, but the plants which grew at Kew were glabrous except for tufts of stellate down about the midrib and axils of the veins beneath; but in Japan a form is commonly much more downy on the leaves and leafstalks. Male catkins 3 in. long; females 8 to 10 in. long; wings of the nut horizontal, broadly crescent-shaped, the whole fruit 3⁄4 to 1 in. across.
Native of Japan; introduced in 1888. It is quite hardy, and in a moist loam would apparently grow well. Professor Sargent found it abundant on Mt Hakkoda at 2,500 to 4,000 ft above sea-level, and almost the largest deciduous tree in that part of Japan.
The only recorded example of this species is one at Borde Hill, Sussex, measuring 50 × 31⁄2 ft (1969).