previous arrow
next arrow


Trees, shrubs or woody climbers with tendrils. Leaves simple, alternate, usually consisting of two lobes or almost bi-foliate with midrib between two leaflets produced as a small spur. Flowers mostly showy, solitary or in few-flowered simple or panicled racemes. Calyx spathaceous, cleft into 2 or 5 teeth at the apex. Petals 5, free, slightly unequal. Stamens 10, or reduced to 5 or sometimes 3. Ovary seated on a stalk  style usually curved, stigma capitate. Fruit a pod, oblong to linear, usually compressed, few to many-seeded, often more or less woody, dehiscent or indehiscent.

Key to the species

Serial Key Reference
1a. Fertile stamen one. Calyx tube long, limb spathaceous B. monandra
1b. Fertile stamens more than one 2
2a. Fertile stamens 10 3
2b. Fertile stamens almost always 3, rarely 4-5 6
3a. Pod dehiscent 4
3b. Pod indehiscent 5
4a. Flowers white, in close axillary racemes; calyx limb susbulately 5-toothed at tip B. acuminata
4b. Flowers yellow, the standard red-bloched within, usually in axi llary pairs; calyx limb entire B. tomentosa
5a. Calyx limb spathceous; flowers in lax recemes; pod falcate, not venulose and not long-beaked. Leaves one-third cleft, pod c 2.5 cm wide B. racemosa
5b. Calyx limb 5-cleft; flowers in short corymbs; pod nearly straight, closely reticulate-venulose along the centre, beaked by long persistent style B. malabarica
6a. Calyx tube very short. Climber with tendrils and stems with a loose undulate centre; laef-lobes usually acute at apex B.scandens
6b. Calyx tube elongated 7
7a. Large climbers with tendrils; leaves deeply cleft; petals densely silky hairy 8
7b. Erect trees; leaves not deeply cleft; petals glabrous 9
8a. Leaves 9-nerved with acute lobes; almost glabrous beneath; calyx limb regularly 5-cleft; pod indehiscent, 2-4-seeded B. macrostachya
8b. Leaves 11-13-nerved with obtuse lobes; densely pubescent beneath; calyx limb regularly 2-cleft; pod at length dehiscent, 8-12-seeded B. vahlii
9a. Calyx limb entire, spathaceous, equalling the cylindric tube; flowers appearing when the tree is almost leafless B. vairegata
9b. Calyx limb entire irregularly 5-cleft; longer than turbinate tube; flowers appearing with leaves B. purpurea