Trees, often with a swollen trunk. Rootstocks often smelling of horseradish. Stipules minute, caducous. Leaves alternate, 2-imparipinnate, with stalked glands at base of petioles and pinnae. Inflorescence a many-flowered axillary panicle. Flowers bisexual, actinomorphic or zygomorphic, with petals and stamens fused into a cup-like hypanthium. Sepals 5, petaloid. Petals 5, alternating with sepals, white. Stamens 5. Ovary superior, of 3 fused carpels. Fruit a long beaked many-seeded pod-like capsule. Seeds with 3 membranous wings.