1Pseudo-stipules absent
1'Pseudo-stipules (a pair of leaflets attached at the base of the petiole) present.
2Neither petiole nor rachis winged
2'Petiole and/or rachis winged
3Sepals (sub)glabrous, as long as the petals
3'Sepals sericeous, shorter than the petals
4Midrib angular beneath; nerves up to 1 cm apart. Inflorescences solitary, simple, up to 5.5 cm long
4'Midrib rounded beneath, nerves at least 1 cm apart. Inflorescences either solitary and widely branched, or simple and fascicled, up to 60 cm long
5Fruits distinctly lobed, lobes spreading, subglabrous
5'Fruits not or slightly, rarely distinctly lobed, lobes erect, densely hairy
6Inflorescences axillary, sometimes together pseudoterminal, up to 5 cm long, hardly branched. Ovary subglabrous
6'Inflorescences terminal and in the upper leaf axils, 25-50 cm long, widely branched. Ovary densely hairy
7Leaflets mostly with glandular-pitted warts. Petal scales not crested. Dry fruit coarsely wrinkled
7'Leaflets without glandular-pitted warts. Petal scales mostly crested. Dry fruit smooth
8Leaves more than 3-jugate. Fruits hardly lobed
8'Leaves (l-)2(-3)-jugate. Fruits distinctly lobed
9Petiole and rachis winged
9'Petiole never, rachis very rarely winged
10Ovary 3- (or 4-)celled. Twigs and leaves glabrous. Leaflets narrow, usually 4-7 times as long as wide, rarely more than 20 by 4 cm, base acute or sometimes rounded
10'Ovary 2-celled. Twigs and leaves sparsely hairy. Leaflets broader, 3-5 times as long as wide, up to 33 by 10.5 cm, base cordate
11Fruits distinctly lobed, lobes spreading.
11'Fruits not or slightly, rarely distinctly lobed, lobes ± erect
12Leaves imparipinnate. Fruits 3-lobed
12'Leaves paripinnate. Fruits nearly always 2-lobed
13Leaves 7-14-jugate. Twigs up to 1 cm in diam., tomentose.
13'Leaves (15-)30-40-jugate. Twigs 1.5-2 cm in diam., glabrous.
14Leaflets with pitted warts looking like small white scales. Leaves mostly imparipinnate, (3-)7-42-jugate. Inflorescences terminal and axillary
14'Leaflets densely finely pitted underneath. Leaves paripinnate or with a reduced terminal leaflet, 1-8(-14)-jugate. Inflorescences rarely terminal
15Nervation open
15'Nervation closed
16Inflorescence and sepals densely hairy
16'Inflorescence and sepals glabrous