Biancaea decapetala

Biancaea decapetala (Roth) O.Deg. (Fabaceae), formerly Caesalpinia decapetala, is a vigorous scrambling, thicket-forming shrub or woody climber native to tropical and warm-temperate Asia and widely naturalised elsewhere, reaching 3–10 m. Stems are stout, ridged, densely covered with stiff, recurved, broad-based prickles and a velvety brownish indumentum on young growth. Leaves are alternate, bipinnate, 20–40 cm long, with 3–10 pairs of pinnae each bearing 6–12 pairs of small, oblong, glabrous to minutely hairy leaflets 1–2 cm long. Showy terminal racemes 15–40 cm long bear bright lemon-yellow flowers about 2.5–3 cm wide with five spreading petals, the upper petal red-streaked, and ten long red-tipped stamens. The fruit is a flattened, oblong, woody legume 6–10 cm long, with a thickened upper margin, tapering to a beak, containing 4–9 brown, ellipsoid seeds.