FABACEAE Lindl. (LEGUMINOSAE Adans.)
Family composed of 765 genera and about 19,580 species, making it one of the most diversified families among Angiosperms, and with almost subcosmopolitan Distribution. It is well represented in North Africa, with no less than 500 species, many of them trees or shrubs.
Traditionally, 3 subfamilies have been recognised primarily based on their floral characteristics: Caesalpinioideae, Mimosoideae and Papilionoideae. However, current phylogeny studies carried out with molecular data do not support this classification, and support the separation of the family into 6 subfamilies (LPGW, 2017). In this new arrangement, the subfamilies Caesalpiniodeae and Papilionoideae are still recognised, but some genera of the ancient Mimosoideae subfamily have been placed under Caesalpiniodeae; the rest are now distributed between 4 new subfamilies: Cercidoideae, Detarioideae, Duparquetioideae and Dialioideae.
Subfam. CERCIDEOIDEAE (Bronn) LPGW
Subfamily composed of 12 genera and about 335 species, mainly distributed across the tropics, although Cercis reaches warm-temperate zones. In fact, C. siliquastrum L. or the Judas tree belongs to this genus, and it is native of southern Europe, but often cultivated as an ornamental in North Africa (Morocco, Algeria and Tunisia). One of its main features are its cordate leaves and its pink flowers arranged in racemes; both the racemes and the pods hang directly from the branches. Bauhinia L. is the only genus in the subfamily with native woody species in North Africa.
Subfam. CAESALPINIOIDEAE DC. (MIMOSOIDEAE DC.)
Subfamily composed of 148 genera and about 4,400 species, distributed mainly in warm regions, tropical and subtropical. In North Africa there is a fair representation of this group of tree and shrub species, to which we should add some introduced and cultivated species grown across the territory for their ornamental value, as fixers of soil, as source of wood, etc., and that in some situations and areas they may have been naturalised. Thus the genus Parkinsonia L., which includes about 15 species distributed in America and Africa, but of which there are no native species in the territory, despite the fact that the well known Jerusalem thorn (P. aculeata L.), native to tropical America, is grown as an ornamental frequently. It is a very attractive tree, both for its yellow flowers and, above all, for its leaves. These are bipinnate, with numerous small leaflets, arranged in 1-3 pairs of pinnae, almost 40 cm long, all starting from a short rachis that is transformed into a spine, as well as the stipules. Then the pinnae seem to be arranged palmately and, once the leaflets had fallen, the secondary, green and photosynthetic rachises persist. Similarly, the genus Gleditsia L., composed of about 14 species native to America and Asia, is represented in the territory by the honey locust (G. triacanthos L.), a native spiny tree of North America cultivated as an ornamental, and characterised by its large and sharp branched spines, and its pendant pods of remarkable size, at first green then turning purple-brown.
Of the genera previously included in Mimosoideae only 4 have native species in the territory: Vachellia Wight & Arn., Senegalia Raf., Faidherbia A.Chev., Prosopis L. and Dichrostachys (DC.) Wight & Arn., while other genera only have cultivated species including Leucaena Benth., Paraserianthes I.C.Nielsen, Albizia Durazz. and Mimosa L.
The genus Dichrostachys comprises some 14 mainly tropical species, with apetalous flowers arranged in spiciform inflorescences. D. cinerea (L.) Wight & Arn., (Mimosa cinerea L., M. glomerata Forssk.), of which various infraspecific taxa are recognised. It is a spiny shrub or small tree, with pantropical distribution, native in Africa typically S of parallel 20. In Sudan, following the Nile valley, it reaches southern Egypt. It has bipinnate leaves with stipular spines, and is unmistakable for its showy, spiciform and pendulous inflorescences, in which the basal flowers are male, with long pink stamens, and the rest hermaphrodite and yellow.
From the genus Leucaena, composed of about 22 species native to the tropical regions of America, there are 2 cultivated species in the territory, both native to Mexico: Leucaena leucocephala (Lam.) de Wit (M. leucocephala Lam., Acacia leucocephala (Lam.) Link), cultivated in Morocco and Egypt, and L. pulverulenta (Schltdl.) Benth. (A. pulverulenta Schltdl.) in Morocco. The former is of great importance as a forage tree, but it is extremely invasive, and therefore it has become naturalised in many parts of the world.
Paraserianthes is a genus with a single species, P. lophantha (Willd.) I.C.Nielsen (A. lophantha Willd.), cultivated in Morocco and Algeria. It is a tree native to Australia, which has been introduced in many parts of the world. It is unmistakable for its spiciform inflorescences with flowers cream or yellowish in colour, with long stamens of the same colour, slightly fused at the base by the filaments.
The genus Albizia composed of some 130 tropical species, is represented in the territory by 3 ornamental species. A. julibrissin Durazz., of tropical Asia, is the most common (Morocco and Algeria), and unmistakable by the well developed whitish-pink stamens, which make extremely attractive flowers. Conversely, A. lebbeck (L.) Benth. (Mimosa lebbeck L.) and A. procera (Roxb.) Benth. (M. procera Roxb.), of tropical Asia, are only grown in Egypt and Libya, and differ from the former by having yellowish-white stamens.
The genus Mimosa is composed of about 510 species worldwide, only M. pigra L. is represented in the territory, a species native to South America (Paraguay and Argentina) and with a remarkable ability to invade, naturalised in Mauritania (in the Senegal River Valley) and cultivated in Egypt. It is a shrub of great size, with spiny stems and leaves, leaves nyctinastic, and flowers in glomeruliform pink capitula, which will turn into hirsute-villous pods, with septa between the seeds, and that will disarticulate into segments in maturity.
Finally, many of the native species of this subfamily [Caesalpinioideae (Mimosoideae)] are protected across different countries in North Africa. In Mali they are all included in its List of species that need authorization for commercial use (Decree 07-155/P-RM of 2007).
Subfam. PAPILIONOIDEAE DC. (FABOIDEAE Rudd.)
This is undoubtedly the most diversified subfamily worldwide, with 503 genera and about 14,000 species, almost subcosmopolitan, with a strong presence across the temperate regions. It is well represented in North Africa, where tree and shrub species are of great importance in the thickets and forests of Mediterranean environments, and also across the semidesert areas.
Numerous native species of this subfamily [Papilionoideae (Faboideae)] are protected in some way in various countries of North Africa. In Mali they are all included in its List of species that need authorization for commercial use (Decree 07-155/P-RM of 2007).
LPGW. 2017. A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny. Taxon 66(1): 44-77.
Key to genera
1 Flowers actinomorphic, bisexual, with radial symmetry; stamens usually more than 10, free 2
1 Flowers ± zygomorphic, bisexual and with bilateral symmetry, or actinomorphic but perianthless (or almost) and unisexual flowers; stamens 5-10, free or fused at the filaments 7
2 Flowers with 10 stamens, with anthers ending in a gland; shrub up to 1 m in height; swollen pods, reniform or heteromorphous Prosopis
2 Flowers with numerous stamens, without a terminal gland; large shrub or tree; pods ± linear, subcylindrical or compressed, or clearly torulose 3
3 Flowers in spiciform inflorescences 4
3 Flowers in globose glomeruli 5
4 Pods wide, very arched Faidherbia
4 Pods narrow, straight or slightly curved Senegalia
5 All or almost all of the leaves reduced to phyllodes Acacia pp
5 Leaves bipinnate, never reduced to phyllodes 6
6 Tree or shrub unarmed Acacia pp
6 Tree or shrub with spines of stipular origin Vachellia
7 Flowers without a perianth or with an inconspicuous perianth, actinomorphic, unisexual, male flower with 5 stamens Ceratonia
7 Flowers with a well developed perianth, ± zygomorphic, with 10 or more stamens 8
8 Flowers with 5 unequal petals -one generally larger than the rest-, often open in the shape of a star; androecium with 10 stamens, free; sepals fused only towards the base 9
8 Flowers papilionoid, with 5 unequal petals: 1 posterior or standard, 2 lateral or wings, and 2 anterior fused forming the keel; androecium with 10 stamens, 9 Stamens usually with fused filaments forming a tube, rarely all free; petals fused through much of their length 11
9 Leaves simple, with leaf blade deeply bipartite or bilobed Bauhinia
9 Leaves pinnate 10
10 Leaves 1-pinnate Senna
10 Leaves 2-pinnate Delonix
11 Plants spiny 12
11 Plants without any spines nor spinescent branches 23
12 Indumentum with most or all hairs bifurcated Indigofera pp
12 Plant glabrous, or with an indumentum with simple hairs only 13
13 Leaves pinnate, with spinescent rachis; corolla pink or white-yellowish 14
13 Leaves simple or trifoliolate; corolla yellow, white, pink, red, purple or violet 15
14 Pod 6-85 mm, stipitate, longer than the calyx or, if shorter, with a non villous calyx, with 2 or more seeds Astragalus
14 Pod 5-6 mm, sessile, surrounded by a villous calyx, with 1 seed Astracantha
15 Corolla violet, blue-purple or predominantly pinkish, red or purple 16
15 Corolla yellow, white or greenish-whitish 18
16 Leaves simple; corolla red or purple; pod lomentaceous Alhagi
16 Leaves simple or trifoliolate; corolla violet, blue, purple or predominantly pinkish; pod no lomentaceous 17
17 Leaves with entire leaflets; corolla violet to blue-purple —exceptionally white—; plant cushion-shaped, with stems and branches rigid and prickly Erinacea
17 Leaves with dentate leaflets; corolla with pink standard, wings and keel white; stems decumbent, neither rigid nor prickly, with simple or geminate spines Ononis pp
18 Leaves reduced to triangular phyllodes in adult stems; calyx divided into 2 lips almost or to the base, laterally flattened; shrubs intricate-spinescent, with highly branched spines 19
18 Leaves well developed in adult stems, although sometimes promptly caducous; calyx divided into 2 lips up to halfway or less, not laterally flattened; shrubs with scattered spines, usually slightly or not branched 20
19 Calyx divided into 2 lips up to the base; lateral branches mostly alternate Ulex
19 Calyx divided up to almost ¼ of the base; lateral branches mostly opposite Stauracanthus
20 Corolla white or greenish-whitish Cytisus pp
20 Corolla yellow 21
21 Calyx slightly bilabiate, circumscissile at anthesis, persisting only the bottomhalf at fruiting Calicotome
21 Calyx clearly bilabiate and persistent, with the upper lip bidentate or bipartite and the lower lip tridentate or trifid 22
22 Upper lip of the calyx bipartite, lower lip trifid and usually larger than the upper lip Genista pp
22 Upper lip of the calyx bidentate, lower lip tridentate, usually similar in size Cytisus pp
23 Stems winged, with 2 clear longitudinal wings along the length of the internodes Pterospartum
23 Stems wingless 24
24 Broom-like plant, with erect, long and thin stems, leafless or with only a fewand small leaves, usually unifoliolate 25
24 Stems erect or not, almost always very foliose, with leaves usually trifoliolate 30
25 Corolla pink or purple; pod is a loment, with clear joints, subspinose, which separated at maturity Taverniera pp
25 Corolla yellow; pod not as a loment, dehiscent or indehiscent, never spiny 26
26 Pods swollen, ± globose, obovoid or reniform; corolla white or yellow Retama
26 Pods ± compressed; corolla yellow 27
27 Calyx bilabiate, with 2 deep lips, upper lip bipartite divided into 2 teeth or segments, and lower lip tridentate Genista pp
27 Calyx only just bilabiate, with 5 subequal teeth, or with the upper lip reduced and the lower lip like a spathe with 5 small distal teeth 28
28 All leaves trifoliolate, or trifoliolate and unifoliolate on the same plant Cytisus pp
28 All leaves unifoliolate 29
29 Corolla 20-30 mm; calyx with the upper lip reduced and the lower lip like aspathe with 5 small distal teeth; pod 4-12 × 0.5-0.8 cm, green and sericeous at first, turning glabrous and dark brown, with 10-18 seeds Spartium
29 Corolla c. 10 mm; calyx with 5 short teeth, subequal; pod 2.5-5 × 0.5-1 cm, glabrous Calobota
30 Stamens free from each other; corolla with a keel almost 2 times longer than the standard Anagyris
30 Stamens all or most of them with fused filaments; keel usually subequal or smaller than the standard 31
31 Stems, leaves and calyces abundantly punctate-glandular, with glands only just or not protruding the epidermal layer, without glanduliferous hairs Cullen
31 Stems, leaves and calyces not punctate-glandular, with or without glanduliferous hairs 32
32 Leaves trifoliolate, with leaflets 6-11 cm long, strongly sericeous on both sides Argyrocytisus
32 Leaves unifoliolate, trifoliolate, paripinnate or imparipinnate with leaflets always less than 3 cm in length, variable hairiness 33
33 Leaves paripinnate or imparipinnate, with 4 or more leaflets 34
33 Leaves unifoliolate or trifoliolate 41
34 Pod highly inflated, membranous-papery, 2-3 cm thick Colutea
34 Pod not inflated, linear-oblong or cylindrical, compressed or not, less than 1.5(2) cm wide or thick 35
35 Pod in loment, with clear joints that separate independentlyat maturity 36
35 Pod not in loment, dehiscent or indehiscent 37
36 Flowers in racemiform inflorescences; pod in clearly compressed joints, flattened, glabrous or hairy, often with spiny surfaces; corolla pink, violet or purple Greuteria
36 Flowers in umbelliform inflorescences; pod with subcylindrical joints ± circular in cross section, glabrous; corolla yellow or pink-purple Coronilla
37 Flowers in long pedunculate glomeruli, terminal oraxillary; corolla white, whitish-pink, yellow, yellowish-orange 38
37 Flowers solitary or in racemiform inflorescences, terminal or axillary; corolla yellow, pink, brown, purple or reddish-purple 39
38 Stems with sericeous indumentum; leaves with (3)4-5 leaflets; corolla white or whitish-pink Dorycnium
38 Stems with villous indumentum; usually leaves with (3)5-19 leaflets; corolla yellow, yellow-orange or whitish-pink Anthyllis pp
39 Corolla yellow Sesbania
39 Corolla pinkish, brown, purple or reddish-purple 40
40 Indumentum with all or almost all hairs bifurcate Indigofera pp
40 Indument with all hairs simple Tephrosia
41 Leaflets with ± dentate margin Ononis pp
41 Leaflets with entire margin 42
42 Corolla pink or purple; pod in loment, with clear joints, spiny, which separated independently at maturity Taverniera pp
42 Corolla yellow; pod not in loment, dehiscent or indehiscent, never spiny 43
43 Pod inflated, cylindrical-subglobose Crotalaria
43 Pod linear-oblong or ovoid, always laterally compressed 44
44 Most of the calyx caducous before anthesis by a circumscissile incisionnear the base; pod 40-60 mm; plant glabrous Hesperolaburnum
44 Calyx persistent persistent in its entirety; pod 3-40(50) mm; plant ± hairy 45
45 Pod with the surface covered in glandular tubercles (except in Adenocarpus anagyrifolius); leaves glabrous Adenocarpus
45 Pod with the surface not covered in glandular tubercles; leaves usually ± hairy 46
46 Calyx bilabiate, with wide lips and subequal in size, upper lip bidentate and lower lip tridentate; or calyx not bilabiate, with an oblique mouth and 5 teeth similar in size Genista pp
46 Calyx bilabiate, with wide lips and subequal in size, upper lip bidentate and lower lip tridentate; or calyx not bilabiate, with an oblique mouth and 5 teeth similar in size 47
47 Corolla (9)13- 35 mm; pod 15-50 mm, linear-oblong; lower leaves trifoliolate, upper leaves trifoliolate or unifoliolate Cytisus pp
47 Corolla 4-6 mm; pod 3-4 mm, ovoid; lower leaves unifoliolate, upper leaves trifoliolate Anthyllis pp
Updated by: J.A. Devesa.