Unarmed trees or shrubs. Leaves bipinnate, not sensitive to the touch, rachis and pinnae without extrafloral nectaries; Stipules not spinescent, inconspicuous and early caducous. Inflorescences consisting of pendulous or erect, pedunculate, spiciform racemes; Flowers pentamerous, uniform, bisexual. Petals valvate, sometimes coherent at base and united for the lower ¼ mm with the stamens, but soon splitting. Stamens 10, free; Seeds red or partly red (in hilar end) and black, obliquely held in pod, ellipsoid, obovoid, orbicular or ovoid-ellipsoid, biconvex, compressed, with a hard testa with areole, wingless, aril absent, but funicle thick, endosperm present;
Asia-Tropical, Australasia, Melanesia present, Solomon Islands present, tropical Asia present
Tropical Asia-Australia and Melanesia (Solomon Islands), 12 species in all, of which 9 in Malesia.
The genus belongs to the ' Adenanthera-group'  of the Mimoseae, characterized by the jointed pedicel with persistent basal part and the alternate leaflets. The African genera Amblygonocarpus and Tetrapleura are both vegetatively and florally indistinct from Adenanthera, the generic characters being derived from the morphology of the pod. Pseudo — prosopis of tropical Africa seems to be more distantly related, having subopposite leaflets and pods with different dehiscence. None of these have red seeds. The present author (Nielsen, l.c.) recently dealt with the specific delimitation. The most important characters are those of the seeds, the indumentum of pedicel, calyx and ovary, and the form of the leaflets. Much work remains to to be done in this genus regarding the development and architecture of the trees. From all over the range of the species systematic collection of flowering and fruiting material from the same specimen is needed in order to get a com plete picture of the diversity.