Japan Flora: Tuberous- rooted twining perennial; stems slender, 100-150 cm. long, with scattered retrorsely appressed short hairs, soon glabrous; leaves petioled, the stipules broadly linear, 3-4 mm. long, 1-ribbed, deciduous, the leaflets 3 or 5, sparsely appressed- hispid on upper side, paler and nearly glabrous beneath, the terminal ovate, acuminate with an obtuse tip, 5-8 cm. long, 2.5-4 cm. wide; racemes 8-15 cm. long, peduncled, with thickened nodes, the pedicels jointed at apex, the bracts broadly linear, 1.5-2 mm. long, the bracteoles lanceolate, acute, about 1 mm. long, caducous; flowers pale greenish yellow, recurved, rather small; calyx with undulate obsolete teeth; legumes about 5 cm. long.- July-Aug. Sunny thick­ ets and forest-borders.

Hokkaido, Honshu, Shikoku, Kyushu. China.