Annual or short-lived perennial up to 1.5 m. tall; stems usually reddish, ridged, shortly appressed strigulose. Leaf-rhachis appressed strigose, up to 20 cm. long, including a petiole of up to 2 cm., prolonged up to 1 cm. beyond lateral leaflets; stipules linear-lanceolate, falcate, up to 15 mm. long and less than one-tenth as wide; petiolules shortly fulvous pubescent, up to 3 or 4 mm. long; leaflets 15–21, elliptic-oblong, ± emarginate, usually 3.5–4 times as long as wide, up to 5 cm. long and 15 mm. wide, mucronate, glabrous above, appressed pilose and the midrib reddish beneath; primary nerves ± 13 on each side, quaternary nerves and pellucid dots visible by transparency. Flowers in terminal and rarely axillary moderately dense many-flowered pseudoracemes, which are usually longer than their peduncles; bracts lanceolate, caducous; pedicels up to 11 mm. long, like the rhachis and calyx covered with short appressed yellow hairs. Calyx-tube ± 2.5 mm. long; teeth acuminate, the upper 2 united for most of their length, shorter than the lower which is about as long as the tube. Standard golden-brown outside, pink or purple within, ± 16 mm. long and wide; keel glabrous, like the standard, wings and filaments gland-dotted. Upper filament lightly attached, much thickened 1.5 mm. above the base; filament-sheath 10–13 mm., free parts 2–3 mm., anthers ± 1 mm. long. Style rather tapering, bent through 80° near the base, not twisted, ± 5 mm. long, pubescent on both sides and ± 0.3 mm. wide in its upper part. Pod spreading or somewhat ascending, upcurved, yellowish, up to 75 mm. long, ± 5 mm. wide, sparsely covered with short (± 0.3 mm.) spreading yellowish hairs. Seeds 9–14 or fewer by abortion, longitudinal, blackish, ellipsoid-oblong, ± 3 × 2.3 × 1.5 mm.; hilum nearly central, the aril small, not above 0.7 mm. long by 0.2 mm. thick.
