1Lateral sepals (alae) caducous at the beginning of fruit-setting. Disk present. Leaves usually with distinct petioles.
1'Lateral sepals (alae) persistent. Disk (apparently) absent. Leaves hardly petiolate. Annual to perennial herbs, sometimes woody at base. Spp. 9-20.
2Annual herbs up to 30 cm high. Flowers, fruits and seeds up to 3 mm long. Spp. 1-3.
2'Shrubs, small trees, or lianas. Flowers, fruits and seeds at least 5 mm long.
3Keel without appendages at apex. Seed without tubercles, without black appendage at chalazal side
3'Keel with a pair of appendages near apex. Seed tuberculate, with a small or large black appendage at chalazal side.
4Capsule narrowly winged, longer than wide. Seed at chalazal side with a cylindrical appendage one third as long as the seed itself
4'Capsule broadly winged, much wider than long. Seed at chalazal side with a small, knob-like appendage
5Fruit much longer than wide, at base with 3 small, persistent sepals. Seed very long-hairy, without aril. Upper sepal flat. Lianas. Sp. 4.
5'Fruit about as long as wide, without persistent sepals. Seed glabrous or shortly hairy, partly covered by an aril. 'Upper' sepal saccate. Shrubs or small trees. Spp. 5-8.
6Flowers 5-6 mm long. Style straight to near stigma. Seed nearly completely covered by the aril
6'Flowers at least 10 mm long. Style curved in apical half. Seed usually covered up to halfway by the aril.
7Capsule covered by a white layer of dense papillae, the wall not with prominent veins. Racemes in the forks
7'Capsule without white layer, with prominent longitudinal veins. Racemes (supra-)axillary.
8Appendages of the keel undivided. Racemes mostly reflexed or patent from the base
8'Appendages of the keel divided into 7—10 ± connate lobes. Racemes erect or very rarely pendulous
9Lateral sepals (alae) broadly ovate, hairy.
9'Lateral sepals (broadly) elliptic or narrower, glabrous or hairy marginally, or rarely covered by stiff hairs.
10Alae yellowish. Ovary and fruit hairy all over. Capsule narrowly winged. Stigma not recurved at apex, with 2 minute lobes
10'Alae green. Ovary and fruit only hairy at margin. Stigma strongly recurved at apex, at inner side with one stigmatic lobe
11Alae nearly symmetric, petaloid (coloured).
11'Alae asymmetric, falcate, not petaloid (green).
12Alae 1.5-2 mm long. Stem set with small, shortly stalked glands. Capsule unwinged. Style obliquely cup-shaped at apex, at one end with a tuft of hairs
12'Alae 3-10 mm long. Stem eglandular. Capsule winged. Style not or hardly widened at apex, without a tuft of hairs.
13Alae mucronate. Style (nearly) straight, (sub)apically with 2 small stigmatic lobes. Filaments nearly completely connate
13'Alae rounded at apex. Style curved in apical half, with one stigmatic lobe. Filaments free for at least one third.
14Alae 6-7 mm long. Capsule hairy along margin. Racemes in the forks (but terminal on side-branches). Bracts and bracteoles persistent
14'Alae 3-4 (in fruit up to 5) mm long. Capsule glabrous. Racemes mostly terminal. Bracts and bracteoles early caducous
15Capsule and vegetative parts stiffly hairy. Appendages of keel little incised. Stigma apically neither widened nor sharply reflexed
15'Capsule glabrous or hairy only at margin. Plants not stiffly hairy. Appendages of keel divided into a number of filiform or finger-shaped lobes. Stigma apically widened or sharply reflexed.
16Capsule c. 2 mm long. Alae c. 3 mm long. Style apically widened, at one side with the stigmatic lobe
16'Capsule (3—)3.5—5 mm long. Alae 4-6 mm long. Style apically strongly reflexed.
17Plant with stiffly erect, long inflorescences. Apical part of the style very asymmetrically winged. Free parts of filaments triadelphous
17'Plant with short inflorescences or, if with long ones, then these ascending. Style apically symmetrically winged. Free parts of filaments not connate.
18Appendages of the keel finely divided into hair-like segments. Capsule almost orbicular, c. 4 by 4 mm
18'Appendages of the keel divided into finger-shaped lobes. Capsule somewhat longer than wide, 2.5-4 by 2.5-3.5 mm.
19Upper petals shorter than the keel, 2.5-3.5 mm long. Capsule at the margin both with curved as well as with short straight hairs. Inflorescences 0.5-2 cm long
19'Upper petals slightly longer than the keel, 2.5-4.5 mm long. Capsule at the margin with curved hairs only. Inflorescences 0.5-7 cm long