Tendriled liana; trunk to 20 cm diam near the ground; pubescence when present appressed, 0.3 mm long; older stems flattened and +/- regularly folded, winged on both sides, the old stem scars thus borne medially; younger stems terete, appressed-pubescent; tendrils simple, watch-spring-like. Leaves simple; petioles 2.5-3.5 cm long, swollen at both ends; blades ovate, usually cleft about one-third their length at apex on mature plants or to the base on younger plants, cordate at base, 6-10 cm long, 4-10.5 cm wide, glabrous above, densely pubescent below, the pubescence appressed-ferruginous, often not conspicuous. Racemes terminal or axillary, to 15 cm long; pubescence on all parts +/- densely appressed-ferruginous; lower flowers opening first, the ovoid flower buds above the flowers conspicuous, longitudinally striate, 4-7 mm long; bracts 1-3, subulate, ca 1 mm long; flowers sweetly aromatic, subsessile; calyx ca 7 mm long and expanding to 13 mm wide in flower, the lobes obtuse, ca 2 mm long; petals 5, white, obovate, 4 of them ca 2 cm long and 1 cm wide, puberulent inside, the fifth petal narrower and shorter, keeled, recurved at apex; stamens 10, of various lengths, some to 8 mm long; anthers held within the keeled petal both above and below the stigma; style stout, its stigma protruding into the keeled petal. Legumes flat, oblong, ca 8 cm long and 2.5 cm wide, glabrous, apiculate at apex on one side; seeds 2-4, disk-shaped, 0.5 cm diam. Croat 10931, 13810. Occasional, in the forest. Flowers February and March (sometimes to April). The fruits apparently mature in the early rainy season, but have been seen only in June. The species loses its leaves in the early dry season. Because this is an exceedingly variable species, it has been placed under many different names throughout its range. Southern Mexico to Bolivia and southern Brazil; Trinidad. In Panama, known from tropical moist forest in the Canal Zone, Colon, San Blas, Veraguas, Panama, and Darién and from premontane rain forest in Coclé.