A deciduous tree, similar in habit and general appearance to Sophora japonica, branchlets glabrous, dark brown. Leaves pinnate, 8 to 10 in. long; leaflets in five and a half to seven and a half pairs, obliquely ovate, pointed; 11⁄2 to 4 in. long, 1 to 11⁄2 in. wide; bright green above, downy on the midrib and stalk, otherwise glabrous at maturity. Flowers white, pea-flower-shaped, 5⁄8 in. long, produced on slender, downy stalks about 1⁄4 in. long, in panicles 4 to 6 in. high, 21⁄2 to 4 in. wide. Pod flat, 2 in. long, 1⁄2 in. wide, tapered to a point at both ends and winged on the seams; seeds three or four, often only one developing.
Native of Japan. This interesting tree was described by Maximowicz as a species of Sophora, but a few years later he transferred it to a new genus – Platyosprion. It is now generally agreed, however, that this species is most at home in Cladrastis. As in all the other species of this genus, the buds are enclosed in the swollen bases of the leaf-stalks, but it is well distinguished from all of them by its stipellate leaflets and by its winged pods.