Perennial herb, prostrate or sprawling or with erect or ascending shoots from a prostrate stem or underground rhizome, rarely erect, 0·2–1·2 m. tall or long, branched.. Branches usually covered with spreading ferruginous hairs or adpressed pubescent.. Leaflets 3, elliptic or almost round, rarely narrowly elliptic, 0·8–7 cm. long, 0·6–3·8 cm. wide, acute or obtuse and mucronulate at the apex, ± rounded at the base, softly pubescent and covered with glands on both surfaces; venation often raised beneath and surface sometimes plicate; petiole 1·1–4·5 cm. long; rhachis 0·5–1 mm. long; petiolules 2 mm. long; stipules mostly brown, lanceolate, 1·1–1·5 cm. long, 3–5 mm. wide, hairy, closely veined.. Racemes terminal and axillary, 2–10 cm. long, 1·4–1·8 cm. wide, above a ferruginous peduncle (3–)5·5–19cm. long; pedicels ±1 mm. long; bracts persistent or deciduous, linear, 6–9 mm. long, 0·5–1·2 mm. wide, hairy.. Calyx with spreading or adpressed silvery hairs, glandular, 4·5–5 mm. long; lobes unequal, triangular, shorter than the tube.. Standard typically dark outside, brownish, crimson, purple or almost black, but in some variants yellow, yellowish or white inside with dark lines, broadly elliptic, 7–8 mm. long, 3–5 mm. wide, glabrous or with very few scattered hairs and median longitudinal area sparsely glandular; wings white or yellow; keel greenish or greenish-yellow, sometimes brown or purple at the apex; all petals with long claws.. Pods oval-oblong, 8–12 mm. long, 6–9 mm. wide, covered with long ferruginous hairs and also with very fine pubescence and glands.. Seeds oblong, brown with purple markings, longest dimension 3·5 mm., shorter dimension 2·5 mm., 1·2 mm. thick; rim-aril white.