Japan Flora: Evergreen climber with woody stem, the branchlets glabrous, but with scattered pale yellow appressed hairs while very young; leaves petiolcd, the leaflets 3, deep green, lustrous, glabrous, but with scattered white appr的sed-hairs while young, with raised finely reticulate veinlets with a free veinlet within the network, the terminal leaflet oblong to elliptic, 7-15 cm. long, 4-8 cm. wide, acumi­nate to acute with a mucro at apex, obtuse at base; racemes 3- to 20-flowered, on peduncles 33-6.5 cm. long, fuscous- velvety, with sparse stinging hairs; calyx densely fuscous- velvety and with sparse stinging hairs; petals dark purple, the keel 6-8 cm. long, incurved and acutely acuminate; legumes about 40 cm. long, 7-sceded, velvety-puberulent, smooth on both surfaces, inflated on the seeds, both margins slightly thickened, not winged; seeds reniform, about 3 cm. long, flat on both surfaces.  May.

Kyushu (Higo Prov.); very rare. China.