Trees, shrubs or herbs, sometimes twinging or climbing. Leaves althernate, sometimes simple but usually with few to many leaflets arranged trifoliately, pinnately, bipinnately or digitately; stipules usually present. Flowers zygomorphic and bisexual, or actinomorphic and osmetimes polygamous; infloresence often terminal, axillary or supra axillary. Calyx campanulate or tubular, 5-toothed, the posterior pair of teeth often ± connate. Petals mostly 5 or sometimes fewer, free or some or all connate, equal or unequal. Stamens commonly 10, rarely only 3 or 7 fetile and fully developed sometimes numerous; filaments variously untied, rarely free. Ovary monocarpellate, superior, unilocular or sometimes falsely plurilocular, ovules one or more borne on posterior suture; style simple, filiform or capitate, al. Fryit a pod (legume), valves usually dry rarely fleshy, usually dehiscent along both sutures or breaking transversely into 1-seeded segments, or indehicent. Seeds often pea- or bean-like, rarely conspicuously arrilate.
Leaves evenly pinnate or bipinnate, sometimes simple or bilobed. Flowers ± zygomorphic, medium-sized to large and showy. Sepals often united at base forming a receptacular cup. Petals 5 or fewer, somewhat unequal, patent. Stamens usually 10, sometimes fewer, filaments usually free.
Trees or shrubs, erect or large tendrillar climbers, bisexual or dioecious. Leaves simple, usually bilobed at apex, palmately veined; stipules usually small, caducous. Flowers in axillary or terminal racemes or panicles. Sepals borne on margin of receptacular tube, free or ± united, calyx sometimes spathe- like.Petals 5, subequal, usually clawed at base. Fertile stamens 3, 5 or 10, staminodes sometimes present. Pods stalked, oblong, linear or elliptic, compressed, leathery or ± woody, dehiscent.
Similar to B. purpurea but leaves broadly ovate, 5-18x5-18cm, apex 1/5-1/3 bifid, lobes obtuse, base cordate, veins 9-11; racemes 1-3cm, flowers ± sessile, receptacular tube 2.5-3cm, buds ovoid, smooth; sepals 2-3cm; petals elliptic, 4-5 x 2.5-3cm, on claws 1.5cm, white or pink, posterior one purple; fertile stamens 5, 4.5-5cm, pods 15-20 x 2-3cm.