KEY TO THE GENERA BASED ON FRUITING MATERIAL

1Fruits indehiscent
1'Fruits dehiscent
2Fruit a woody or fleshy drupe, spherical to ellipsoid
2'Fruit variously winged or enclosed within the calyx lobes, not a drupe
3Leaves always simple
3'Leaves trifoliolate or pinnate
4Fruit outwardly little different from flowers, the calyx lobes scarcely enlarged and not or only slightly spreading, the styles long and protruding
4'Fruit markedly different from flowers, the wings well developed
5Fruit a samara, the carpel wall laterally extended into 3 chartaceous wings with distinct reticulate venation
5'Fruit a pseudosamara, the ovary little enlarged from the flowering stage, supported by 4 considerably enlarged, spreading woody sepals
6Leaves verticillate
6'Leaves opposite and decussate
7Carpels 2; seeds hairy, not winged
7'Carpels 2-6; seeds glabrous, winged
8Indumentum including stellate hairs and often spherical glandular trichomes that dry orange. Valves of capsule sometimes joined by a replum after dehiscence.
8'Indumentum of simple hairs only and lacking spherical orange glandular trichomes. Valves of capsule not joined by a replum after dehiscence
9Fruit simple; carpels always 2 and seeds up to 40 per locule (New Guinea and New Britain)
9'Fruit multiple; carpels 2-5 and seeds 1 to few per locule (New Britain and New Ireland)