An erect woody, annual or short-lived perennial shrub or small tree, 1–4 m tall with a deep taproot (to 2 m). Young stems are angled and pubescent. Leaves trifoliate, alternate, set in a spiral around the stem; leaflets oblong, lanceolate, 2–10 cm long and 2–4 cm wide, pubescent; discolourous - green above, greyish-green below. Lateral petioles 2–3 mm long, terminal one 10–20 mm; stipules linear, 2–3 mm long. Flowers usually yellow, sometimes with purple or red streaks or plain red; calyx 10–12 mm long with 5 linear teeth