Lianas, woody. Young branches and inflorescences rusty pubescent; tendrils strong, solitary, pubescent. Stipules caducous; petiole 3-8 cm, rusty pubescent; leaf blade suborbicular to ovate-orbicular, 10-18 × 10-20 cm, subleathery, abaxially thinly rusty pubescent, densely pubescent on veins, adaxially glabrous except near petiole, primary veins 11-13, veins dense, base deeply cordate, apex bifid to 2/5-1/2 on flowering branches, lobes obtuse or rounded at apex. Inflorescence a corymbose panicle, ca. 13 cm, terminal or axillary; bracts lanceolate; bracteoles opposite, linear, inserted at middle of pedicels. Pedicel 10-15 mm, rusty pubescent. Flower buds ellipsoid. Receptacle funnelform, ca. 3 mm; calyx lobes 5, not reflexed, broadly ovate, 1 free, others in 2 adnate parts, ca. 6 mm, outside pubescent. Petals pinkish or white, broadly obovate, 8-9 mm with a claw ca. 1 mm, abaxially rusty hairy, shortly clawed, margin crisped. Fertile stamens 3; filaments ca. 25 mm, glabrous. Staminodes 2, ca. 7 mm. Floral disk fleshy. Ovary stalked, glabrous; style slender, glabrous; stigma capitate, small. Legume oblong, compressed, ca. 22 × 6 cm; valves hard woody, glabrous. Seeds 5-10, obovoid, compressed, ca. 20 mm. Fl. Dec, fr. next Apr.