1 "Leaves pinnate, or appearing pinnate with 2 or more pinnae arising from a rudimentary rachis" 2 1 "Leaves bipinnate with obvious rachis and rachillas" 6 2 "Lateral veins of leaflets very closely spaced and extending right to the leaflet margin; leaflet apex usually conspicuously emarginate (Haematoxylum campechianum)" Haematoxylum 2 "Lateral veins of leaflets widely spaced, looping before reaching the leaflet margin, or veins all +/- longitudinal or veins obscure; leaflet apex not or scarcely emarginate" 3 3 "Stems with a spine at each node; leaf rachis strongly flattened (Parkinsonia aculeata)" Parkinsonia 3 "Stems unarmed; leaf rachis not flattened" 4 4 "Filaments of the 3 abaxial stamens sigmoidally curved and many times longer than their anther; pods indehiscent; glands absent from leaf rachis and petiole" Cassia 4 "Filaments of all stamens straight or arcuately curved, less than twice as long as their anther; pods usually dehiscent; glands usually present on leaf rachis or petiole" 5 5 "Anther thecae glabrous; pedicels lacking bracteoles" Senna 5 "Anther thecae ciliolate; pedicels with 2 bracteoles in upper half" Chamaecrista 6 "Stems and rachises without spines" 7 6 "Stems or rachises armed with straight or curved spines" 11 7 "Leaflets 35-60 mm long, alternating along rachilla (Erythrophleum chlorostachys)" Erythrophleum 7 "Leaflets 2-22 mm long, in opposite pairs along rachilla" 8 8 "Rachis, rachillas and leaflets all glabrous; all leaflets with stipellae (Caesalpinia pulcherrima)" Caesalpinia 8 "Rachis, rachillas or leaflets hairy; stipellae absent" 9 9 "Brown to black glandular hairs present on rachis, rachillas, stems, pedicels and sepals; leaflets glabrous and with at least a few black punctate glands near the margins (Erythrostemon gilliesii)" Erythrostemon 9 "Glandular hairs absent; leaflets at least sparsely hairy, punctate glands absent" 10 10 "Leaflets 13-22 mm long; hairs on rachis and rachillas very dense, rusty; petals yellow; pods 5-10 cm long (Peltophorum pterocarpum)" Peltophorum 10 "Leaflets 6-13 mm long; hairs on rachis and rachillas sparse to moderately dense, white; petals red; pods 15-40 cm long (Delonix regia)" Delonix 11 "Leaflets, rachis and rachillas glabrous (Ticanto crista)" Ticanto 11 "Leaflets, rachis or rachillas sparsely to densely hairy" 12 12 "Stems with straight spines 30-100 mm long, often branched; rachises unarmed; tree (Gleditsia triacanthos)" Gleditsia 12 "Stems and rachises with curved prickles to 7 mm long; scrambling shrubs or vines" 13 13 "Largest leaflets 27-80 mm long; ovary with bristles; pods prickly" Guilandina 13 "Largest leaflets 8-27(-35) mm long; ovary smooth; pods smooth" 14 14 "All or most leaflets alternating along rachilla; pods with a wing (along upper suture) 3-10 mm wide" Mezoneuron 14 "All leaflets in opposite pairs along rachilla; pods not winged (Biancaea decapetala)" Biancaea