Vigna nuda N.E.Br.

Leguminosae, J. B. Gillett, R. M. Polhill & B. Verdcourt. Flora of Tropical East Africa. 1971

Morphology General Habit

Perennial herb from a thick, often extensively branched, frequently horizontal woody rootstock; nearly always flowering before the leaves appear.

Morphology Stem

Stems at first erect, later prostrate or, less often, climbing, 6 cm. to 1·8 m. tall or long, glabrous or puberulous on the leafy shoots, densely pubescent or setulose when young but later glabrescent.

Morphology Leaves

Leaflets 3, ovate-oblong, lanceolate or subrhomboid-oblong, the laterals slightly oblique, 3·5–9·5 cm. long, 0·4–6·5 cm. wide, usually the terminal subhastate or almost 3-lobed at the base, obtuse at the apex, cuneate, rounded or minutely subcordate at the base, mostly rather leathery, glabrescent or rather roughly pilose on both surfaces; venation raised and closely reticulate on both surfaces; petioles 3–13 cm. long; rhachis 1–2·6 cm. long; petiolules 2–5 mm. long; stipules rather distinctly appendaged when well developed, ovate to lanceolate, 0·4–1 cm. long, 1–3 mm. wide, but usually slightly bilobed or almost truncate.

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, at first appearing caespitose from short undeveloped stems, 2–5-flowered; rhachis 2–3 cm. long; peduncle erect, 4–20 cm. long, shortly rather roughly pubescent; pedicels 1–3 mm. long; bracts at base of peduncles in leafless state are short stipules; true bracts oblong, 1–3 mm. long, 1–1·5 mm. wide, ribbed, deciduous; bracteoles oblong-lanceolate, 1–2·5 mm. long, 0·5–0·7 mm. wide, ribbed, soon deciduous.

Morphology Reproductive morphology Flowers Calyx

Calyx sparsely to moderately pubescent; tube 4 mm. long; lobes narrowly triangular, 2–5 mm. long, subequal, the upper pair joined for half their length or almost to quite free.

Morphology Reproductive morphology Flowers Corolla

Standard often greenish or yellow-brown outside, marked with purple inside, pink to purple or mauve with a patch of yellow at the base, rounded or transversely elliptic, 1·5–2·3 cm. long, 1·8–3 cm. wide, emarginate, glabrous; wings and keel usually dull mauve, the latter sometimes white, twisted as well as incurved and bearing an upwardly directed pocket on left-hand petal.

Morphology Reproductive morphology Fruits

Pods erect, linear-cylindrical, usually compressed, 7–11 cm. long, 4–7 mm. wide, sparsely puberulous and gland-dotted, 12–14-seeded.

Morphology Reproductive morphology Seeds

Seeds yellow to dark purple, ellipsoid or oblong-reniform, often keeled, longest dimension 5·5–8 mm., shorter dimension 3–4 mm., 2–3 mm. thick; hilum central, 1·5–3 mm. long; rim-aril slightly developed, blackish-green.

Habitat

Seasonally burnt upland grassland; ± 2000 m.

Distribution

T7