Small to medium-sized tree. Bark, greyish, smooth,armed with cone-shaped knobs, tipped with short straight spines. Leaves essentially imparipinnate but terminal leaflet often missing, citrus aromatic when crushed; rhachis grooved on top; leaflets in 4-8 opposite or alternate pairs, ovate to elliptic, up to 4 × 2 cm, basal pair smallest, increasing in size towards the the ultimate pair, translucent gland dots present along the crenate-dentate margin. Flowers in short, branched terminal heads, small, greenish-white. Fruit c. 5 mm in diameter, brownish-red, splitting to reveal a shiny black seed.