Plants evergreen shrubs or trees up to 6 m tall, with slender, often pendulous branches. Leaves with short petioles and rachises, the rachises extended into a straight, well-developed spine, with1-3 pairs of pinnae with flattened rachises, each pinna with many, opposite to alternate leaflets; leaflets 2-7 mm long, 1.2.5 mm wide, oblong to oblong-elliptic, glabrous. Racemes up to 20 long, lax. Flowers: sepals 6-7 mm long; petals 8-12 mm long, 6-8 mm wide, ovate-rhombic, yellow, the upper one with red markings, a rounder blade and longer claw. Pods 3-15 cm long, 0.6-0.8 cm wide, constricted into oblong or elliptic segments, pointed or beaked, the sides coriaceous, diagonally striate, eventually dehiscing along the upper suture; seeds 7.5-10 mm long, 3.5-4 mm wide, oblong-ellipsoid, brownish, sometimes mottled.
Parkinsonia aculeata is native to tropical and subtropical America but it is widely cultivated as an ornamental species, for shade, and as a windbreak and sometimes becomes naturalized.