Key to the genera of the Bunchosia clade
1. Anthers poricidal, opening by oblique subapical pores; fruit dry and breaking apart into 3 mericarps at maturity, each mericarp bearing 4–10 flattened elongated lateral winglets and often a dorsal crest or winglet as well; palaeotropics.
1. Anthers dehiscing longitudinally by introrse slits (as in most Malpighiaceae); fruit fleshy and indehiscent or dry and dehiscent or indehiscent, when dehiscent the mericarps nearly smooth or bearing many long slender vascularized setae; neotropics.
2. Sepals all eglandular.
3. Leaves consistently opposite; vegetative hairs stellate (i.e., with a stalk and several branches); sepals completely concealing petals in enlarging bud; stamens glabrous; fruit rugose, each mericarp with a prominent dorsal ridge or rudimentary winglet but otherwise lacking outgrowths; southeastern Brazil and adjacent Paraguay and Bolivia.
3. Leaves alternate or alternate and opposite or rarely all opposite; vegetative hairs typically malpighiaceous (i.e., with a stalk and 2 branches); sepals leaving outermost petals exposed in enlarging bud; stamens densely hairy; fruit bearing many long slender vascularized setae; Mexico.
2. Sepals (the lateral 4 or all 5) bearing 8–10 large abaxial glands, these only very rarely rudimentary.
4. Trees or shrubs; calyx glands sessile; glands on lamina of leaves (if present) impressed in abaxial surface; fruit fleshy, indehiscent; throughout the neotropics from Mexico and the Caribbean to southern South America.
4. Woody vines, occasionally described as shrubs or small trees; calyx glands peltate, raised on stout stalks; glands on lamina of leaves borne on margin near base; fruit dry, dehiscent; Cuba and southern South America.
5. Petals abaxially densely appressed-tomentose on claw and whole surface of limb; mericarps bearing many long slender vascularized setae; Cuba.
5. Petals abaxially only thinly sericeous on claw and proximally on midrib of limb; mericarps smooth-sided, the only outgrowth a rudimentary dorsal crest; southern Brazil, Paraguay, and northeastern Argentina.