KEY TO THE GENERA Based on fruiting material

1Leaves simple.
1'Leaves compound, usually imparipinnate, sometimes tri- or unifoliolate, rarely pseudoparipinnate or paripinnate.
2Leaves decussate
2'Leaves spiral or alternate.
3Calyx caducous, calyptriform. Petals caducous, or persistent and enlarged (wing-like) in fruit
3'Calyx persistent (except in some specimens of Buchananid), distinctly 4- or 5-lobed.
4Fruit developed from an inferior ovary and crowned with persistent floral parts.
4'Ovary and fruit superior and subtained by the persistent floral parts.
5Petals persistent, usually (much) enlarged, wing-like, and reflexed in fruit
5'Petals usually caducous and not enlarged in fruit.
6Fruit with a distinct or conspicuous hypocarp.
6'Fruit without a hypocarp.
7Leaf lower surface not papillose. Fruits reniform
7'Leaf lower surface often papillose. Fruits not reniform
8Fruits incompletely 2-celled. Seed curved. Leaves usually with dense or sparse, minute, peltate or lobed scales on both surfaces
8'Fruits 1-celled. Seed or embryo (if testa confluent with endocarp) straight. Leaves without scales like above.
9Fruit with 3-5 stigmas or vestiges of undeveloped carpels close to one side at the base 1. Buchanania,
9'Fruit without stigmas or such vestiges of undeveloped carpels.
10Fruits subglobose, ½-⅔ cm Ø
10'Fruits larger, usually longer than wide; if globose or subglobose then (1—)2½ or more cm Ø.
11Fruits glabrous; flesh juicy and without black varnish. Leaves glabrous, not papillose beneath
11'Fruits hairy; flesh thin and full of black varnish. Leaves often hairy and/or papillose beneath in most species
12Leaflets with a distinct, continuous, intramarginal vein
12'Leaflets without such intramarginal vein.
13Calyx (much) enlarged and lobes wing-like in fruit
13'Calyx not enlarged in fruit.
14Lower surface of leaflets with domatia.
14'Lower surface of leaflets without domatia.
15Domatia not hairy, each of them like a pit or cavity. Fruits obliquely subglobose, less than 1 cm Ø
15'Domatia hairy, each of them consisting of a tuft of hairs.
16Climbers. Fruits broad-ellipsoid or slightly reniform, 1¼-1½ by c. 4/5 cm; flesh full of black varnish
16'Trees.
17Fruits 1-celled; endocarp coriaceous, not hard
17'Fruits 5-12-celled; endocarp woody and hard.
18Endocarp with an operculum covering each cell
18'Endocarp without such opercula
19Leaflets usually 10-16 pairs. Fruits broad-ellipsoid, obtuse at both ends, 2½-4 by 1ll2-2ll2 cm
19'Leaflets usually 2-7 pairs, sometimes tri- or unifoliolate.
20Endocarp with 1 (or 2) distinct operculum (opercula) at the apical end.
20'Endocarp without distinct operculum (opercula).
21Fruits c. 1 cm long. Seed reniform. Young twigs, leaflets, and inflorescences with stellate hairs
21'Fruits larger, 2-2½ cm long. Seed oblong. Young twigs, leaflets, and inflorescences with simple hairs
22Fruits scurfy outside, lanceolate, 2½ by 1 cm. Leaflets velutinous on the lower surface
22'Fruits glabrous, variously shaped but not lanceolate, less than 1½ by ⅔ cm.
23Fruits ± oblong, or obliquely broad-ellipsoid; style or its scar excentric.
23'Fruits obliquely subglobose, or globose; style or its scar terminal.
24Fruit with style or its scar on one side at the upper ⅓.Terminal leaflet similar to the lateral ones
24'Fruit with style or its scar lateral at the apical end. Terminal leaflet usually very small, reduced, or not developed
25Leaves distinctly imparipinnate, tri- or unifoliolate. Endocarp free from exocarp and mesocarp when ripe
25'Leaves pseudoparipinnate or paripinnate. Endocarp united with exocarp and mesocarp when ripe