Deciduous trees or shrubs; branches armed with spines. Leaves alternate, paripinnate and bipinnate, often on the same plant, leaflets numerous, margin usually serrate or crenate; stipules small. Inflorescence an axillary spike-like raceme, rarely a panicle. Flowers bisexual or unisexual. Sepals 3–5, subequal; petals 3–5, unequal, as long or only slightly exceeding sepals, greenish-yellow; stamens 6–10, anthers dorsifixed; ovary subsessile, ovules 2–numerous. Pod indehiscent, oblong, compressed; seeds 2–many, transversely flattened.
About 16 species from North and South America, Asia and Africa; 1 species naturalised in Australia.