a	Leaves simple, emarginate apically to deeply bilobed, sometimes with a pair of leaflets
	b	Leaves pinnately or bipinnately compound with more than 2 leaflets, very seldom leaves reduced to green, ± terete, 'needle-like' pinna-rachillae with or without minute inconspicuous leaflets, or the rachillae laterally winged and appearing flattened, '± phyllodial', with many pairs of small leaflets

	a	Petals 0 Leaves with a single pair of leaflets
	b	Petals 5 Leaves emarginate apically to deeply bilobed, occasionally with a single pair of leaflets

	a	Stamens (8-)10(-12) Inflorescence an axillary or terminal panicle Leaflets with a midrib and lateral nerves or without a midrib but with 3-6 conspicuous nerves arising from the base Pods pale yellowish brown, reniform, indehiscent Seeds with small sticky reddish resin glands	Colophospermum
	b	Stamens 20-25 Inflorescence a slender raceme or panicle Leaflets with 7-12 prominent nerves arising from the base, without a midrib Pods brown or reddish brown, obliquely semiorbicular, ovate or ovate-oblong, dehiscent or indehiscent Seeds not as above	Guibourtia

	a	Plants with trailing or climbing, mostly herbaceous stems arising from a large underground tuber Tendrils usually present Fertile stamens 2, accompanied by staminodes Calyx with the 2 upper sepals partly or completely fused, the rest free	Tylosema
	b	Plants growing as a shrub or small tree, seldom scandent or climbing but then woody and without tendrils

	a	Flowers normally unisexual and plants dioecious Female flowers with the stigma sessile on the ovary, capitate, flattened-globose Male flowers with 10 fertile stamens Calyx turbinate with 4 or 5 short broad lobes	Piliostigma
	b	Flowers bisexual Style elongate Fertile stamens 1-10 Calyx spathaceous or campanulate with 5 short lobes or teeth

	a	Calyx spathaceous, splitting to the base down one side only, with the sepals fused or sometimes partly separated Fertile stamens 1-10, sometimes accompanied by staminodes Pods oblong or oblanceolate-oblong, valves thinly woody	Bauhinia
	b	Calyx campanulate, with 5 short teeth or lobes Fertile stamens 10 Plants often conspicuously glandular Pods semiorbicular, valves papery, with or without stalked glands	Adenolobus

	a	Leaves reduced, the pinna-rachillae green, ± terete and 'needle-like', with or without minute inconspicuous leaflets, or the rachillae laterally winged and appearing flattened, '± phyllodial', with many pairs of leaflets up to 9 x 3 mm Plant armed with stout spines	Parkinsonia
	b	Leaves not reduced, pinna-rachillae not 'needle-like' or '± phyllodial' Plant unarmed or armed with recurved prickles, rarely armed with spines

	a	Leaves bipinnate
	b	Leaves simply pinnate

	a	Plant unarmed
	b	Plant armed with prickles or spines

	a	Leaflets alternate Flowers small (petals 2-5 mm long, white to cream-coloured or pale green) Sepals open from a very early stage, leaving the petals covering the flower until anthesis
	b	Leaflets opposite Flowers usually medium to large (petals 7-32 mm long, seldom smaller, yellow, orange, red or magenta) Sepals valvate or imbricate

	a	Flowers pedicellate Petals narrow, ± densely pubescent, at least on the margins Anthers 0.5-0.75 mm long Stigma minute, cup-shaped-punctiform on a narrow conical style Stamen filaments pubescent or tomentose to near the apex Hairs (when present) on vegetative buds and young branchlets grey-brown to yellowish	Erythrophleum
	b	Flowers sessile Petals glabrous or almost so Anthers 1.5-2.0 mm long Style very short, ending in a funnel-shaped stigma slit down one side Stamen filaments glabrous Hairs on vegetative buds, young branchlets and inflorescence axes rusty red	Burkea

	a	Leaves imparipinnate Herb or low shrub up to 0.5 m high Stems, leaves and calyces with many dark sessile glands Petals up to 9 mm long	Hoffmannseggia
	b	Leaves paripinnate Tree or large shrub Petals 7-32 mm long

	a	Stigma broadly peltate Inflorescence axes, calyces and ovaries rusty tomentose Petals yellow Stipules up to 14 mm long, linear-subulate with up to 7 linear, alternate lateral appendages up to 6 mm long	Peltophorum
	b	Stigma not broadly peltate Inflorescence axes, calyces and ovaries not rusty tomentose Petals yellow, pink, red or magenta Stipules not as above	Caesalpinia

	a	Calyx lobes valvate Flowers small, greenish to white Spines usually branched	*Gleditsia
	b	Calyx lobes or teeth imbricate Flowers yellow, pale yellowish white, pink, red or magenta Spines not branched

	a	Petals 2-3 mm long Pods samaroid, with a basal seed-containing portion whose upper suture is greatly extended beyond the seed-containing part and is broadly winged on its lower side	Pterolobium
	b	Petals 6-25 mm long Pods unwinged	Caesalpinia

	a	Plants armed with spines
	b	Plant unarmed

	a	Leaves with 3 pairs of opposite leaflets Inflorescence a relatively few-flowered lateral or terminal raceme Petals yellow, 8-10 x 5-7 mm Ovary glandular	Haematoxylum
	b	Leaves with (3-)5-10(-12) pairs of subopposite or irregularly alternate leaflets Inflorescence a short, lax panicle or many-flowered, drooping raceme Petals greenish or white Ovary eglandular

	a	Inflorescence a lax panicle Pods 30-50 mm long, 9-12 mm wide, straight or almost so, dehiscent	Umtiza
	b	Inflorescence a dense drooping raceme Pods large, 150-300 mm long, 25-35 mm wide, usually slightly falcate but often twisting with age, indehiscent	*Gleditsia

	a	Bracteoles paired, valvate throughout, well developed, completely enclosing the flower bud, usually persistent
	b	Bracteoles nonvalvate, often scale-like, often caducous or 0, seldom enclosing the flower bud, but, if so, then one or both margins of one bracteole overlapping the other, at least at the base, and the flower with only 1 petal

	a	Bracteoles enclosing the young flower bud but soon caducous, exposing the bud enclosed by the calyx Stamen and staminode filaments all united basally for ± half their length Fertile stamens 3, alternating with 5 sterile teeth or short filaments Larger petals 3, subequal, gold with red veins	Tamarindus
	b	Bracteoles enclosing the young flower bud and persistent below the open flower Stamens not as above and more than 3 fertile Petals or tepals not coloured as above

	a	Perianth clearly differentiated into 5 obvious petals and 5 sepals	Julbernardia
	b	Perianth 0 or of 1-7(-11) parts, usually 4-7 all sepaloid and of similar form, grading inwards from broader to narrower	Brachystegia

	a	Petals 0 or sometimes petals present but reduced to minute, linear, inconspicuous filaments and apparently absent
	b	Petals 1-5, well developed

	a	Stamens 10, filaments united basally for 1.5-3.5 mm, tube entire or split down one side Calyx leathery, 4-(rarely 5-)lobed, red or scarlet, glabrous or sparingly puberulous Ovary glabrous Inflorescence a dense, congested, subglobose panicle, usually cauliflorous on older branches but occasionally terminal	Schotia
	b	Stamens 5-10, filaments free Sepals 5, fulvous or rusty brown puberulous outside Ovary densely ferruginous-hirsute Inflorescence a many-flowered panicle or raceme

	a	Inflorescence a many-flowered panicle Ovules 2 Pod ovoid-ellipsoid, densely brown velutinous-puberulous	Dialium
	b	Inflorescence a dense raceme Ovules many Pod elongated, compressed, thick and coriaceous, glabrous	*Ceratonia

	a	Petals 1-4
	b	Petals 5

	a	Petals 1, pubescent and green outside, dark red inside, 25-45 mm long, with a long claw suddenly widening into a deeply bilobed lamina 22-31 mm wide Fertile stamens usually 7 (rarely 9)	Afzelia
	b	Petals 1-4, pale pink or red throughout, smaller than above and not widened above into a deeply bilobed lamina Fertile stamens 10	Schotia

	a	Anthers opening by terminal or basal pores or short slits, usually basifixed Petals mostly yellow Glands often present on petiole or leaf rachis
	b	Anthers opening by longitudinal slits which are as long as the anther, usually dorsifixed Petals pink, red, mauve, magenta or sometimes yellow Conspicuous glands not present on petiole or rachis

	a	Filaments of the 3 adaxial stamens sigmoidally incurved, many times longer than their small anther Filaments of other stamens straight, shorter, the anthers dehiscing by basal pores Pedicels 2-bracteolate at or just above their base Pod elongate, usually cylindric, indehiscent Seed coat smooth, without areoles Tree	Cassia
	b	Filaments of all stamens straight, either shorter or not more than twice as long as their anthers, if longer, then the anthers dehiscing by apical pores Pods various, but if cylindric and indehiscent then the pedicels without bracts

	a	Bracteoles 0 Pod either indehiscent, or breaking inelastically through one or both sutures, if through both, then the valves not coiling Androecium often irregular, the members tending to decrease in size from the abaxial to the adaxial side of the flower Anther thecae naked along the sutures Seed coat often with a closed areole on each face or margins Tree, shrub or herb	Senna
	b	Bracteoles 2 Pod elastically indehiscent, the valves coiling at or after dehiscence Androecium virtually regular, the two cycles sometimes of different lengths but not decreasing regularly from abaxial to adaxial side of the flower Anther thecae ciliolate along the sutures Seed-coat without areoles Usually a herb	Chamaecrista

	a	Petals yellow Small shrub to 2 m high Leaves up 12 mm long with 3 pairs of obcordate or broadly obovate to obovate-suborbicular leaflets	Haematoxylum
	b	Petals pink, red, mauve or magenta Large shrub or tree Leaves much larger than above

	a	Inflorescence a short raceme or panicle Calyx glabrous or almost so Petals pink, red or scarlet Ovary glabrous or almost so	Schotia
	b	Inflorescence a stout raceme up to 350 mm long Sepals densely fulvous-tomentose outside Petals pink, mauve or magenta Ovary fulvous-tomentose	Baikiaea