1	"Inflorescences capitate"	2
1	"Inflorescences spicate"	4
2	"Prickles solitary, scattered along the stems"	"Senegalia brevispica"
2	"Prickles in 3s or, if solitary, located at the nodes"	3
3	"Prickles in 3s; rachises of pinnae usually with a recurved prickle near the tip"	"Senegalia hamulosa"
3	"Prickles usually solitary; rachises of pinnae without a recurved prickle near the tip"	"Senegalia densispina"
4	"Prickles usually in pairs near the nodes, sometimes absent or almost so"	5
4	"Prickles in 3s or solitary near the nodes, almost always present"	10
5	"Pinnae with 1-2 pairs of leaflets; pedicels (0.5-)0.75-1.5 mm long"	"Senegalia mellifera"
5	"Pinnae with 3 or more pairs of leaflets; pedicels up to 0.5 mm long"	6
6	"Calyces puberulous; riverine trees"	"Senegalia rovumae"
6	"Calyces glabrous; plants shrubs or trees, of varied habitats"	7
7	"Bark yellowish, papery, flaking; pods puberulous"	8
7	"Bark not as above; pods glabrous or almost so"	9
8	"Leaflets 0.75 -2.5 mm wide; pods 0.9-1.1 cm wide"	"Senegalia ankokib"
8	"Leaflets 3.5-11 mm wide; pods 1.7-2 cm wide"	"Senegalia manubensis"
9	"Leaves with 2-3 pairs of pinnae; each pinna with 3-5 pairs of leaflets; plants shrubs or small trees"	"Senegalia laeta"
9	"Well-developed leaves with more than 3 pairs of pinnae, each pinna with more than 5 pairs of leaflets; plants large trees"	"Senegalia goetzii"
10	"Rachises of pinnae  with a recurved prickles on the lower surface at or near the tip"	"Senegalia hamulosa"
10	"Rachises of pinnae without a recurved prickle at or near the tip, sometimes the leaf rachises terminating in a prickle or with prickles on their lower surface"	11
11	"Filaments 13-18 mm long; leaves with 1 pair of pinnae, each pinna with 2-4 pairs of leaflets; leaflets 5-17 mm long, 3-13 mm wide"	"Senegalia ogadensis"
11	"Filaments less than 10 mm long; leaves and leaflets various, not as above in all respects"	12
12	"Petioles with a large flattened gland 1-3 mm in diameter"	13
12	"Petioles usually with glands less than 1 mm in diameter, occasionally up to 1.2"	14
13	"Petioles 13-28 mm long, the gland basal; pods 1.8-2.2 cm wide, densely puberulous"	"Senegalia condyloclada"
13	"Petioles 2-6 mm log, the gland at the point of attachment of the lowest pair of pinnae; pods 0.9-1 cm, wide, glabrous"	"Senegalia caraniana"
14	"Leaflets 8-19 mm long, 5-13 mm wide; pods (2-)3.2-4.8 cm wide with glabrous, thin, more or less crinkly valves"	"Senegalia zizyphispina"
14	"Leaflets smaller; pods less than 2 cm wide or, if wider, puberulous and not crinkly"	15
15	"Pinnae with 2-3 pairs of leaflets"	16
15	"Most pinnae with 4 or more pairs of spikelets"	17
16	"Pods densely and shortly appressed pubescent and with yellowish glands"	"Senegalia densispina"
16	"Pods glabrous"	"Senegalia somalensis"
17	"Flowers pink; inflorescences 12-18 mm long, with 7-15 flowers; pods completely glabrous"	"Senegalia moggii"
17	"Flowers white or cream; inflorescences longer, usually with 20 or more flowers; pods pubescent, at least near the base"	18
18	"Stems whip-like, with long slender branches from a basal cushion of short, vegetative branches"	19
18	"Stems not as above"	20
19	"Prickles in 3s; leaves with 3-8 pairs of pinnae; pods 1-2 cm wide"	"Senegalia cheilanthifolia"
19	"Prickles solitary; leaves with 1-2(-3) pairs of pinnae; pods (1.2-)1.4-1.9 cm wide"	"Senegalia flagellaris"
20	"Leaves with a prominent gland present between the lowest pair of pinnae; petiolar glands absent"	"Senegalia ochracea"
20	"Leaves lacking a gland between the lowest pair of pinnae; petiolar glands usually present"	21
21	"Bark grey, rough; nodes of branchlets less than 3 cm apart; pods mostly 2.5-8 cm long"	"Senegalia senegal"
21	"Bark yellowish-brown, flaking; nodes of branchlets mostly 3-4 cm apart; pods mostly 8-15 cm long"	"Senegalia circummarginata"