Decumbent to erect annual or short-lived perennial, up to 1.8 m tall; branches subappressed pubescent to spreading hirsute. Leaves 3-foliolate, sometimes mostly on short shoots; leaflets 4–50 × 2–15 mm, linear or oblanceolate to elliptic-oblong or obovate, hairy on both surfaces or only beneath; petiole 2–30 mm long; stipules 1–3 mm long, subulate to attenuate-triangular. Racemes usually of two sorts; primary racemes terminal or leaf-opposed on long shoots, 2–40 cm long, laxly 3–40-flowered, indeterminate (ending in a bud) or determinate (ending in a bristle-like extension of the rhachis); supplementary inflorescences usually developed (at least later in the season) from short shoots in axils of the main leaves, with 1–2 flowers on a filiform axis 0.2–2.5 cm long; bracts 0.5–4 mm long, linear-subulate to linear-lanceolate, usually shorter than the pedicel; bracteoles on the pedicel, setaceous. Calyx 3.5–9 mm long, pubescent; lobes narrowly attenuate-triangular (rarely somewhat oblong and apiculate in subsp. pauciflora), 1.5–2.5 times as long as the tube, lanate along the inner margins (particularly of the lower lobes) when young. Standard broadly elliptic, yellow, often lined red, pubescent or rarely almost glabrous outside; wings broadened upwards, nearly as long as the keel; keel 6–12(14) mm long, angular, with a narrow twisted beak. Pod shortly stipitate, 8–15 × 5–9 mm, ± oblong-obovoid (sometimes only slightly broadened apically), pubescent outside and sometimes also inside, 6–10(12)-seeded. Seeds 2.2–3 mm long, oblique-cordiform, smooth, brown.
