Erect much-branched sometimes slightly viscid subshrub, 1–2 m. tall, mostly blackening on drying. Stems pubescent with tubercular-based hairs or, in some areas, glabrescent. Leaves sensitive, 10–40-foliolate; leaflets linear-oblong, 0.6–1.5 cm. long, 1–4 mm. wide, rounded but mucronulate at the apex, obliquely rounded at the base, entire, glabrous; venation obscure; petiole and rhachis together 1–6 cm. long, with tubercular-based hairs; petiolules 0.5 mm. long; stipules oblong-lanceolate, straight, spurred, 0.6–1.6 cm. long, 1–2.5 mm. wide, soon falling. Inflorescences leaf-opposed, 3–7-flowered; rhachis 1.5–8 cm. long; peduncle 1–1.5 cm. long; pedicels 2–5 mm. long; bracts 4–5 mm. long, 1–1.5 mm. wide, deciduous; bracteoles ovate-elliptic, 2.5–3.5 mm. long, 1.5 mm. wide, ciliate. Calyx glabrous or ciliate, 2-lipped, the lips broadly oblong, 3.5–4 mm. long, 2.5–3 mm. wide, one emarginate, the other 3 toothed at the apex. Standard yellow, often flushed purplish-red or apricot outside, rounded, 7–8 mm. long, 5–6 mm. wide, emarginate; keel-petals yellow, not laciniate. Pods stipitate, linear, straight or slightly curved, 3–4.5 cm. long, (4–)6–9-jointed, the suture somewhat constricted between the articles; articles ± oblong, 4–6 mm. long, 4–5 mm. wide, compressed, very sparsely pubescent or at length glabrous, raised in the middle but smooth save for a slightly raised venation. Seeds dark chestnut, oblong-ellipsoid, compressed, shiny, almost beaked at one end of the hilum, longest dimension 3.2 mm., shorter dimension 2.2 mm., 1.8 mm. thick. Fig. 54/10, p. 366.