Tree-like, erect, compact shrub, up to 3 m high, reseeder, forms dense stands. Stems green, glabrous, glandular, and striate when young, becoming greyish tan with blackish vertical fissures and white lenticels. Stipules minute, subulate, spreading, senescent. Leaves 3-foliolate, flat, dark green, glabrous. Leaflets linear-oblong, acute at base, obtuse and mucronate at apex, densely gland-dotted, glabrous, terminal longest. Inflorescences axillary, 1-flowered; pedicels stout, as long as leaves. Flowers purple and white, held above the subtending leaf. Cupulum apical, 3-fid, teeth subequal. Calyx: lobes unequal, ovate, obtuse, nigro-punctate, glabrous. Petals: standard suborbicular, purple, with violet flash, veins deep purple; wings white, longer than keel. Flowering time Nov.-Apr.