Description: Annual and perennial herbs with twining stems, rarely erect.
Leaves alternate, pinnately 3-foliolate; lateral leaflets asymmetric; stipules and stipels present.
Inflorescences racemose, axillary; peduncles long; bracts and bracteoles deciduous. Calyx 5-lobed, upper 2 often united. Standard broader than long; keel truncate, obtuse or beaked. Stamens diadelphous; anthers uniform. Ovary with several ovules; style narrowing at base, bearded; stigma terminal.
Pod ± cylindrical, dehiscent, straight or curved; seeds without obvious aril.
Distribution and occurrence: World: 100–150 species, mainly tropical, chiefly Africa & Asia. Australia: c. 10 species (c. 5 species native, other species introduced), all mainland States.
Text by C. Gardner & T. A. James
Taxon concept:
Taxa not yet included in identification key
Vigna racemosa
| | Key to the species | |
| 1 | Leaflets linear to narrow-lanceolate or narrow-ovate, to 15 mm wide | 2 |
| Leaflets elliptic to ovate, rhombic or more or less circular, more than 15 mm wide | 3 |
| 2 | Stems sparsely to densely hairy with spreading to appressed, more or less bristly rusty-brown hairs; flowers mostly 20–30 mm long; pod 4–14 cm long with spreading bristly hairs | Vigna vexillata |
| Stems glabrous or sparsely hairy with appressed, whitish hairs; flowers 7–10 mm long; pod 2–5 cm long, glabrous or with a few, appressed hairs
Back to 1 | Vigna lanceolata |
| 3 | Leaflets wide-elliptic to more or less circular, apex emarginate or obtuse; confined to coastal dunes and headlands | Vigna marina |
| Leaflets elliptic to rhombic or ovate, apex acute to acuminate (often obtuse in Vigna lanceolata); not confined to coastal dunes and headlands
Back to 1 | 4 |
| 4 | Stipules peltate, ovate, rhombic or obovate, mostly 8–15 mm long; stem hairs conspicuously spreading, yellow-brown, mostly 1–1.5 mm long | Vigna radiata |
| Stipules not peltate, more or less ovate to lanceolate 2–3 mm long; stems glabrous or with appressed to more or less spreading whitish hairs c. 1 mm long
Back to 3 | 5 |
| 5 | Apex of leaflets acute to acuminate, base rounded to cuneate; flowers 12–25 mm long | Vigna luteola |
| Apex of leaflets acute to obtuse, base usually wedge-shaped; flowers 7–10 mm long
Back to 4 | Vigna lanceolata |
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