1Fruit wall glabrous inside, endocarp thick, sclerenchy matous, radially striate from the attachment of the seed and separating from the pericarp in ripe fruit. Arillode very thick. Calyx and petals punctate, calyx margin slightly membranous. Leaves 3-6-jugate, leaf rachis always glabrous. Inflorescence at least 17 cm long
1'Fruit wall hairy inside, at least on the sutures of the carpels, endocarp thin, charta-ceous, not radially striate, not separating from the pericarp in ripe fruit. Arillode thin or thickened only towards the base. Calyx and petals usually not punctate, calyx margin not membranous. Leaves 1-4-jugate, leaf rachis usually hairy, at least when young. Inflorescence up to 18 cm long
2Stipe of fruit 5-6 mm long. Arillode not alate. Petioles up to 5.5 cm long; leaflets very coriaceous. Petal claw 0.4-0.6 mm long
2'Stipe of fruit 2-3 mm long. Arillode alate. Petioles longer than 6 cm; leaflets subcoriaceous to chartaceous. Petal claw 0.2-0.3 mm long
3Indumentum of patent, críspate hairs
3'Indumentum of straight, usually rather appressed hairs
4Leaves 1- or 2-jugate, rachis (excluding petiole) up to 5.5 cm long; nerves marginally indistinctly looped. Calyx teeth (sub)glabrous inside. Flowering twigs 1.5-5 mm thick
4'Leaves 4-jugate, rachis (excluding petiole) over 13 cm long; nerves marginally distinctly looped. Calyx teeth densely puberulous inside. Flowering twigs more than 5 mm thick
5Bracts triangular, 0.3-1 mm long; pedicels at anthesis longer than 1.5 mm. Calyx deeply incised. Claw of petal usually longer than 0.2 mm
5'Bracts narrowly triangular, 0.8-1.5 mm long; pedicels at anthesis up to 1.5 mm long. Calyx connate up to ⅓. Claw of petal up to 0.2 mm long.
6Inflorescence rachis up to 15 cm long. Often several petals more or less reduced, at most hairy on outside and on margin, less than 1 mm long, about as long as the calyx
6'Inflorescence rachis not longer than 5 cm. Petals all developed, hairy on both sides, more than 1.5 mm long, slightly longer than the calyx
7Petal blade ovate to suborbicular to obovate; scales free, almost linear, often one reduced, apex usually forked. Apex of leaflets acuminate.
7'Petal blade elliptic to semiorbicular; scales adnate to margin up to halfway, equal in size, apex broadened. Apex of leaflets rounded to slightly acuminate
8Leaves (2-) 3- or 4-jugate, rachis (excluding petiole) up to 10.5 cm long; leaflet index up to 5, apex acuminate to caudate. Pedicels elongating up to 10 mm in fruit
8'Leaves all 1- or 2-jugate, rachis (excluding petiole) up to 5(-7.5) cm long; leaflet index less than 3.6, apex retuse to acuminate. Pedicel elongating up to 7 mm in fruit
9Domatia large sacs, opening on top. Calyx 0.8-1.1 mm high. Petals never longer than calyx, (sub)pilose inside. Disc pilose. Margin of hypocotyl pilose
9'Domatia often pustular sacs to pockets, rarely pits, opening in front, rarely on top. Calyx 1-1.5 mm high. Petals often slightly longer than calyx, glabrous inside. Disc glabrous, rarely pilose. Margin of hypocotyl glabrous
10Arillode thick towards base, 2-layered. Leaves 1- or 2-jugate; domatia usually present; nerves basally indistinctly looped, midrib below usually (sub)puberulous, tertiary venation slightly to distinctly scalariform. Stigma not or very slightly lobe.
10'Arillode thin, 1-layered. Leaves always 1-jugate; domatia always absent; nerves distinctly looped, midrib below glabrous, tertiary venation reticulate. Stigma distinctly lobed in fruit
11Cotyledons (obliquely) above each other. Petals about as long as calyx, petal blades triangular to rhomboid to ovate, scales free. Anthers up to 1.3 mm long. Nerves indistinctly looped submarginally
11'Cotyledons beside each other. Petals shorter than calyx, scales adnate to margin. Anthers c. 0.6 mm long. Nerves with distinct submarginal loops towards the apex only
12Petals inside (sub)glabrous. Disc usually pilose. Venation above about the same colour as lamina. Style up to 2 mm long in fruit
12'Petals inside rather hairy. Disc glabrous. Venation above usually yellowish to reddish. Style up to 3 mm long in fruit. (Anther curved, connective slightly protruding)
13Fruit wall inside completely pilose. Domatia many (sunken) sacs, opening on top. Leaflets broadly oblong-elliptic to -obovate, index up to 2.1; nerves on lower sur face of leaflets almost flat, up to 14 mm apart; both surfaces of leaflets the same colour when dried
13'Fruit wall inside hairy on sutures only, rarely also on valves, but then always with a glabrous patch in the centre. Domatia many to few (rarely completely absent), often pustular sacs or pockets, opening in front. Leaflets ovate to elliptic, index up to 3.8; nerves on lower surface of leaflets raised, up to 35 mm apart; lower surface of leaflets usually more brownish than upper surface when dried