Plants unarmed trees. Leaves bipinnate, witnout specialized glands although sometimes with glandular hairs at the base of the pinnae; leaflets small, opposite. Flowers usually large, in short, axillary corymbose racemes; sepals 5, valvate; petals usually 5, sometimes 1 or 3, all alike or the upper one differing in color and shape; stamens 10, exserted, filaments hairy below; ovary subsessile to shortly stipitate, with many ovules. Pods linear-oblong, flattened, dehiscent; valves coriaceous or woody, septate between the seeds; seeds transverse, har, oblong, subcylindrical to flattened and oblong-elliptic.
Delonix has 9 species, two of which grow from east Africa to India. The other 7 are all native to Madagascar. One of them, Delonix regia ("Flame tree") is widely cultivated.