A unique characteristic of the species is the flower color variation within natural populations. Wiliwili is adapted to and lowland environments and has potential for revegetation of degraded sites. Spreading branches are stiff, and the broad thin crown is wider than it is high. The bark is smooth, light to reddish brown, and has scattered stout grey or black spines up to 1 cm long. With age, it becomes slightly fissured and thin.
Twigs are stout, green with yellow hairs when young and have scattered blackish spines.
Leaves are alternate, compound, 13-30 cm long, with a long slender leafstalk. The three leaflets are short-stalked. The end leaflet is larger than the other two. Flowers are crowded in a mass and are 7.5-15 cm long and short stalked. Reports vary on flowering and leaf fall.