Vigna monophylla Taub.

Erect, climbing or trailing herb, 14–60 cm. tall, with slender often woody fusiform tuberous roots up to 7 cm. long and 1·5 cm. wide.. Stems angled, glabrous or with sparse hairs.. Leaves unifoliolate; leaflets ovate to oblong-lanceolate or ±elliptic, 1·8–11·5 cm. long, 0·5–3 cm. wide, acute or rounded but mucronulate at the apex, rounded or very slightly emarginate at the base, glabrous or with a few hairs on the midrib beneath, margins sometimes ciliolate, ± 3-nerved from the base; venation raised and reticulate; petiole ±1·5 cm. long; stipules persistent, lanceolate, 3–4 mm. long, 1·5 mm. wide.. Racemes with rhachis 5–12 mm. long; peduncle 7–35 cm. long, ±winged, puberulous with stiff blackish hairs towards the apex or rarely glabrescent or pale; pedicels 1 mm. long; bracts and bracteoles ±deciduous, ovate-oblong, 1–2 mm. long.. Calyx glabrous or densely covered with small adpressed blackish hairs; tube ±2 mm. long; lobes ±1·5–2·5 mm. long.. Standard variously described as green, apricot, mauve, yellow or white but mostly purple, deeper inside and tinged greenish outside, round, 1–1·4 cm. long and wide, glabrous; wings purplish or green inside and magenta outside; keel greenish or white, often tipped with mauve.. Alternate anthers with a pair of glands at their base.. Pods held ±erect, cylindrical, 3·8–5 cm. long, 3–4 mm. wide, tomentellous to densely covered with dark brown hairs.. Seeds reddish-brown, often speckled blackish, subglobose to cubic, 2–2·5 mm. in diameter.. Fig. 98, p. 662.

It is a tropical plant. It grows in open woodland and wet grassland. It grows between 1,000-1,800 m above sea level.