Parkinsonia aculeata is a small deciduous tree or shrub approximately 3–7m tall. The trunk and branches are green and photosynthetic.
It has raceme inflorescences with 3–30 flowers, each 1–2.5cm wide.
Flowers have 5 yellow petals, the upper petal with pink spots.
The fruit is a long brown pod with 1–5 oval seeds.