Description from
Flora of China
Sophora japonica Linnaeus, Mant. Pl. 1: 68. 1767.
Anagyris chinensis Sprengel; Macrotropis foetida Candolle; Ormosia esquirolii H. Léveillé; Pongamia chinensis Candolle; Robinia mitis Loureiro (1790), not Linnaeus (1763); Sophora angustifoliola Q. Q. Liu & H. Y. Ye ["angustifiola"]; S. japonica f. columnaris Schwerin; S. japonica f. hybrida Carrière; S. japonica f. oligophylla Franchet; S. japonica f. pendula Loudon; S. japonica var. praecox Schwerin; S. japonica var. pubescens (Tausch) Bosse; S. japonica f. variegata Nichols; S. japonica var. vestita Rehder; S. japonica var. violacea Carrière; S. mairei H. Léveillé (1915), not Pampanini (1910); S. pubescens Tausch; S. sinensis Forrest; S. vaniotii H. Léveillé; Styphnolobium japonicum (Linnaeus) Schott.
Trees, to 25 m. Bark gray-brown, longitudinally striate; branches of current year green, glabrous. Leaves 15-25 cm; stipules ovate to linear, caducous; petiole inflated at base, bud hidden; leaflets 9-15; stipels subulate; blades ovate-lanceolate or ovate-oblong, 2.5-6 × 1.5-3 cm, papery, glaucous and sparsely to densely pubescent abaxially, usually becoming glabrate, base broadly cuneate or rounded, apex acuminate, mucronate. Panicles terminal, to 30 cm; bracteole subulate. Calyx shortly campanulate, 3.5-4.5 mm; teeth 5, obtuse, pubescent. Corolla white or creamy yellow, rarely purple-red; standard broadly ovate, claw short, base cordate, apex retuse; wings ovate-oblong, ca. 10 × 4 mm; keel similar to wings, but broader. Stamens 10, unequal, free, persistent. Ovary glabrescent. Legumes green, moniliform, 2.5-5 × ca. 1 cm, obviously constricted between seeds, indehiscent, fleshy. Seeds 1-6, yellow-green, black-brown when dry, ovoid. Fl. Jul-Aug, fr. Aug-Oct.
Many intergrading varieties and horticultural forms exist that are not worthy of recognition at this level. Sophora angustifoliola appears to be merely a narrow-leaved form of this species.
Styphnodendron, formerly regarded as part of Sophora, is represented in Asia only by S. japonicum, and that isn’t even directly related to Sophora.
Cultivated throughout China [native to Japan and Korea; widely cultivated elsewhere].
