Vigna radicans Welw. ex Baker

Leguminosae, B. Mackinder, R. Pasquet, R. Polhill and B. Verdcourt. Flora Zambesiaca 3:5. 2001

Habit

Annual or perennial trailing or entirely prostrate herb, up to 1.8 m long, or sometimes suberect and short, c. 15 cm tall.

Stem

Stem densely covered with spreading yellowish or dark brown bristly hairs.

Leaflets

Leaflets 3, even on the first nodes, 3–10 × 1–7 cm, ovate to lanceolate in outline, entire to 3-lobed or pinnatifid (lobes up to 9, the basal ones sometimes bifid at the apex), subacute and mucronulate at the apex, rounded to cuneate at the base, appressed bristly pubescent on both surfaces; tertiary venation closely parallel and at right-angles to the midrib; petioles 2–26 cm long; rhachis 0.5–3 cm long; stipules 4–10 × 1.5–3 mm, lanceolate, multinerved, prolonged and subcordate at the base.

Inflorescences

Peduncle 4–25 cm × 0.5–1 mm, pubescent; rhachis 1–2-noded, internodes 1–2 mm long.

Flowers

Flower mauve to purple, 11–18 × 13–20 mm; pedicel c. 1 mm long, not expanding as the pod matures; bracteoles 1.5–6 mm long, linear-lanceolate, usually 1-nerved, rarely multinerved.

Calyx

Calyx densely covered with white or brown bristly hairs; tube 3–4 mm long; lobes 5–9 mm long, linear-lanceolate, subequal, the upper pair joined for two-thirds of their length.

Corolla

Standard with 2 parallel widely spaced appendages; keel without a beak or pocket, not twisted or slightly twisted towards the left.

Ovary

Ovary 5–9-ovuled.

Fruits

Pods erect, 4–5 cm × 4–5 mm, linear-cylindrical, sparsely covered with appressed white or dark brown bristly hairs, with a curved beak.

Seeds

Seed 3.5–6.5 × 2.5–3.5 × 2–5 mm; rim aril developed as two parallel lines.