1	"Mature leaves appearing simple (phyllodes); flowers in heads or spikes and these 1–several in each axil or in racemes or panicles"	Acacia
1	"Mature leaves bipinnate"	2
2	"Terminal pair of pinnae modified to tendrils; rainforest lianes"	Entada
2	"Terminal pair of pinnae bearing ordinary leaflets"	3
3	"Leaflets distinctly alternate to subopposite"	4
3	"Leaflets opposite"	5
4	"Leaf axes lacking extrafloral nectaries; pod opening on both sutures, not coloured within; seeds scarlet or red and black; stamens 10, free"	Adenanthera
4	"Leaf axes with extrafloral nectaries; pod opening on 1 suture, orange or red within; seeds brown; stamens numerous, united basally"	"Pararchidendron {Pararchidendron pruinosum}"
5	"Leaf axes lacking extrafloral nectaries"	6
5	"Leaf axes with extrafloral nectaries"	8
6	"Stamens united at least basally, numerous; pod dehiscing by valves recurving elastically from tip to base"	"Calliandra {Calliandra surinamensis}"
6	"Stamens free"	7
7	"Stamens 10 in perfect flowers; basal flowers sterile with elongate flat filaments; pod opening on both sutures"	Neptunia
7	"Stamens as many as or twice as many as corolla lobes; basal flowers not sterile; pod dehiscing in 1-seeded segments, the marginal portion persistent"	Mimosa
8	"Flowers in distinct spikes or spicate racemes"	9
8	"Flowers in rounded to oblong heads or, if spicate, then some basal flowers imperfect"	18
9	"Stamens 10, free"	10
9	"Stamens numerous, free or united"	11
10	"Pod indehiscent, filled with pulp surrounding seeds; most or all flowers perfect"	Prosopis
10	"Pod not as above; only apical flowers perfect"	Dichrostachys
11	"Stamens united basally"	12
11	"Stamens free, rarely basally united"	13
12	"Flowers in solitary or paired axillary racemes; leaflets 1.5–4 mm wide; seeds oval to elliptic, 3–4 mm thick"	"Paraserianthes {Paraserianthes lophantha}"
12	"Flowers in panicles of short spikes; leaflets 1–1.5 mm wide; seeds ±oblate, flat, c. 1.5 mm thick"	"Falcateria {Falcateria toona}"
13	"Inflorescences elongated racemes (>1 cm long) or paniculate; stipules inconspicuous; prickles absent"	14
13	"Inflorescences simple (peduncles solitary or clustered) or in very short racemes <5 mm long"	15
14	"Leaf rachises with nectary glands; flowers sessile within the heads"	Acacia
14	"Leaf rachises without nectary glands; flowers distinctly pedicellate within the heads"	"Acaciella {Acaciella angustissima}"
15	"Peduncles with an involucel of bracts above the base (sometimes at apex of peduncles and hidden by flowers); stipules spinescent, at least on young plants; prickles absent"	Vachellia
15	"Peduncles without an involucel of bracts; stipules not spinose (but stems sometimes armed with non-stipular prickles)"	16
16	"Branches armed with recurved prickles"	Senegalia
16	"Branches unarmed"	17
17	"Leaf rachises with nectary glands; flowers sessile within the heads"	Acacia
17	"Leaf rachises without nectary glands; flowers distinctly pedicellate within the heads"	"Acaciella {Acaciella angustissima}"
18	"Peduncles bearing 2 conspicuous, ±foliaceous bracts; pod nearly circular to broadly oblong, stipitate"	Neptunia
18	"Peduncles lacking such bracts; pod variable in form"	19
19	"Pod dehiscing in 1-seeded, indehiscent segments"	"Cathormion {Cathormion umbellatum}"
19	"Pod dehiscing otherwise"	20
20	"Stamens 5 or 10, free; petals free"	21
20	"Stamens numerous, free or united"	22
21	"Flowers all perfect; pod broadly oblong or linear-oblong, 15–27 mm wide"	"Leucaena {Leucaena leucocephala}"
21	"Flowers near base of head male or sterile; pod narrowly linear, flat, to 4 mm wide"	Desmanthus
22	"Stamens free"	23
22	"Stamens united at least basally"	28
23	"Inflorescences elongated racemes (>1 cm long) or paniculate; stipules inconspicuous; prickles absent"	24
23	"Inflorescences simple (peduncles solitary or clustered) or in very short racemes <5 mm long"	25
24	"Leaf rachises with nectary glands; flowers sessile within the heads"	Acacia
24	"Leaf rachises without nectary glands; flowers distinctly pedicellate within the heads"	"Acaciella {Acaciella angustissima}"
25	"Peduncles with an involucel of bracts above the base (sometimes at apex of peduncles and hidden by flowers); stipules spinescent, at least on young plants; prickles absent"	Vachellia
25	"Peduncles without an involucel of bracts; stipules not spinose (but stems sometimes armed with non-stipular prickles)"	26
26	"Branches armed with recurved prickles"	Senegalia
26	"Branches unarmed"	27
27	"Leaf rachises with nectary glands; flowers sessile within the heads"	Acacia
27	"Leaf rachises without nectary glands; flowers distinctly pedicellate within the heads"	"Acaciella {Acaciella angustissima}"
28	"Seeds embedded in pulpy mesocarp of indehiscent pod"	"Samanea {Samanea saman}"
28	"Seeds and pod not as above"	29
29	"Seeds with a pleurogram, without a wing; pod opening on both sutures"	Albizia
29	"Seeds lacking a pleurogram, winged or not"	30
30	"Pod opening along 1 suture, commonly reddish externally and orange-reddish within; seeds unwinged; leaflets 1–5 (–6)-jugate"	Archidendron
30	"Pod opening along both sutures, commonly brownish, not brightly coloured either inside or out; seeds with a narrow, peripheral, membranous wing; leaflets 1.5–11-jugate"	Archidendropsis