Family:
Fabaceae Lindl.

Acacia Mill.

This genus is accepted, and its native range is W. Indian Ocean, Borneo to Pacific.

[FZ]

Leguminosae, J.P.M. Brenan. Flora Zambesiaca 3:1. 1970

Morphology General Habit
Trees or shrubs, sometimes climbing; the native species in our area almost invariably armed with prickles or spines, the introduced ones usually unarmed.
Morphology Leaves
Leaves 2-pinnate or (in introduced species) often modified to phyllodes (entire leaflike often flattened organs without pinnae or leaflets); pinnae each with one to many pairs of leaflets; gland on the upper side of the petiole usually present; glands also often present at the insertion of the pinnae.
Morphology Reproductive morphology Flowers
Flowers in spikes, spiciform racemes or round heads, hermaphrodite or male and hermaphrodite; if in heads then central flowers not enlarged and modified; inflorescences usually axillary, racemose or paniculate.
Morphology Reproductive morphology Flowers Calyx
Calyx (in our species) gamosepalous, subtruncate or usually with 4-5 teeth or lobes.
Morphology Reproductive morphology Flowers Corolla
Corolla 4-5(7)-lobed.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens many, fertile, their filaments free or (in A. albida and A. eriocarpa) connate into a tube at their extreme base only; anthers (at least some) glandular at the apex, or all eglandular (in all native species glandular except in A. albida, in introduced species mostly eglandular).
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary stipitate to sessile, glabrous to puberulous.
Morphology Reproductive morphology Fruits
Pods very variable, dehiscent or sometimes indehiscent, flat, ± compressed, or sometimes cylindric, straight, curved, spiral or contorted, continuous or moniliform.
Morphology Reproductive morphology Seeds
Seeds unwinged, often with a hard smooth testa, without endosperm.

[FTEA]

Leguminosae, J. B. Gillett, R. M. Polhill & B. Verdcourt. Flora of Tropical East Africa. 1971

Morphology General Habit
Trees or shrubs, sometimes climbing; the native species in our area almost invariably armed with prickles or spines, the introduced ones usually unarmed
Morphology Leaves
Leaves bipinnate or (in introduced species) often modified to phyllodes (entire, leaf-like often flattened organs, without pinnae or leaflets); pinnae each with one to many pairs of leaflets; gland on upper side of petiole usually present; glands often also present at insertion of pinnae
Morphology Reproductive morphology Flowers
Flowers in spikes, spiciform racemes or round heads, hermaphrodite or male and hermaphrodite; if in heads then central flowers not enlarged and modified; inflorescences usually axillary, racemose or paniculate
Morphology Reproductive morphology Flowers Calyx
Calyx (in our species) gamosepalous, subtruncate or usually with 4–5 teeth or lobes
Morphology Reproductive morphology Flowers Corolla
Corolla 4–5(–7)-lobed
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens many (from 35–40 in A. lahai to about 215 in A. thomasii) , fertile, their filaments free or (in A. albida) connate into a tube at their extreme base only; anthers (at least some) glandular at apex, or all eglandular (in all native species glandular except in A. albida, in introduced species mostly eglandular)
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary stipitate to sessile, glabrous to puberulous
Morphology Reproductive morphology Fruits
Pods very variable, dehiscent or sometimes indehiscent, flat, ± compressed, or sometimes cylindrical, straight, curved, spiral or contorted, continuous or moniliform
Morphology Reproductive morphology Seeds
Seeds unwinged, often with a hard smooth testa, without endosperm.

[FSOM]

M. Thulin et al. Flora of Somalia Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Trees or shrubs, sometimes climbing; the native species almost always armed with prickles or stipular spines, the introduced ones usually unarmed
Morphology Leaves
Leaves bipinnate or, in introduced species, modified to phyllodes; gland usually present on upper side of petiole, glands often also present at insertion of pinnae
Morphology Reproductive morphology Flowers
Flowers in spikes, spike-like racemes or heads, bisexual or polygamous, sometimes enclosed in bud by a ring of bracts, the involucel, the remnants of which remain on the peduncle
Morphology Reproductive morphology Flowers Calyx
Calyx usually 4–5-lobed, or subtruncate
Morphology Reproductive morphology Flowers Corolla
Corolla 4–5(–7)-lobed
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens many
Morphology Reproductive morphology Flowers Androecium Stamens Filaments
Filaments free, or (in A. albida) connate at the base
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anthers glandular at apex, or (in A. albida and A. saligna) eglandular
Morphology Reproductive morphology Fruits
Pods very variable, dehiscent or sometimes indehiscent, flat to ± thickened, straight, curved, spiral or contorted.
Distribution
Some 1100 species, mostly tropical and subtropical, the majority in Australia, some 40 maybe native in Africa.
Note
Acacia was subdivided along the lines indicated in vol. 1: 368 (1993), species n. 1–20, and also A. petrensis, would belong to Senegalia and species n. 22–39, as well as A. cernua, A. qandalensis and A. tephrophylla, would belong to Vachellia. Only species n. 44, A. saligna, introduced from Australia, would remain in Acacia. A. albida, according to molecular evidence, should be placed in the monotypic genus Faidherbia A. Chev. The record of A. ancistroclada Brenan from C Somalia in Kuchar, The plants of Somalia (1988) was based on Gillett & al. 21978 and 22451 that are respectively A. tortilis and A. nilotica subsp. leiocarpa. A. farnesiana L. has been reported as cultivated near Mogadishu according to Kuchar (1988). As this has not been confirmed by any specimen the record is omitted here. A. pseudonigrescens Brenan & Ross, only known from near Mustahil in SE Ethiopia may well occur in Somalia. It is a very characteristic species, apparently unarmed, with a smooth grey powdery bark and leaves with 1 pair of pinnae, each with 2 pairs of leaflets, 18–35 x 11–31 mm.

[LOWO]

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Note

Tribe Acacieae is widely attributed to Bentham (1842), e.g., Vassal (1981) and Maslin et al. (2001), but Reveal (1997) gives Dumortier (1829) as the first place of publication of the tribe and this is confirmed by Brummitt (pers. comm., 2004). The genus Faidherbia A.Chev. was included in the Acacieae by Vassal (1981), and is still retained as part of the tribe by Maslin et al. (2003). The tribal position of Faidherbia remains equivocal, although Lewis & Rico Arce (this volume) place the genus in tribe Ingeae following Polhill (1994) and Luckow et al. (2003) rendering the Acacieae monogeneric, with the single genus Acacia. The taxonomic status of Acacia and its relationship to other mimosoid genera is, however, as yet unresolved. At present three subgenera are recognised within Acacia sens. lat.: Acacia, Aculeiferum and Phyllodineae. Pedley (1986) proposed that these three subgenera be given generic rank, namely Acacia, Senegalia Raf. and Racosperma Mart., respectively, but this was not widely adopted, although the debate surrounding these suggested nomenclatural changes continues. Pedley (2003) has recently published combinations (several hundred of which are new) in Racosperma for all Australian phyllodinous acacias. What is clear is that the genus Acacia, as currently circumscribed, is not monophyletic (Maslin et al., 2003; Miller & Bayer, 2003; Miller et al., 2003), and at least five genera should be resurrected or newly described from within it in due course. The five genera correspond to those recognised by Pedley except that Senegalia sens. lat. is regarded as comprising three genera: Senegalia sens. strict., Acaciella Britton & Rose (synonym Acacia subgenus Aculeiferum section Filicinae (Benth.) Taub.), and an undescribed genus based on Acacia coulteri Benth. and a small group of related species. Acacia subgenus Acacia appears more closely related to tribe Mimoseae and subgenus Phyllodineae nests within the Ingeae in most recent studies (Luckow et al., 2003). While these two taxa are not moved out of the Acacieae in this treatment, this seems a likely future consequence of recent research. Removal of Acacia sens. strict. from the Acacieae would leave the tribe without its type genus so that Acacieae could then no longer be retained. It is not appropriate here to reinstate, change or describe new generic names, especially as application of the names Acacia and Racosperma are currently under review (Maslin et al. 2003, Orchard & Maslin, 2003; Luckow et al., submitted b). A proposal to retypify Acacia based on an Australian taxon (Orchard & Maslin, 2003) has recently been passed by the Committee for Spermatophyta but this decision awaits ratification. The present treatment of the Acacieae thus recognises a single genus containing c. 1450 species (Fig. 26).

Vernacular
florists' mimosa
Habit
Armed or unarmed trees, shrubs and lianas
Ecology
Wide ranging in habitat, from rain forest to alpine communities, dominant shrubs and trees in seasonally dry tropical and subtropical bushland, woodland, wooded grassland, coastal dunes and deserts
Distribution
Acacia sens. strict. (syn.: Acacia subg. Acacia; Vachellia), c. 161 spp., pantropical (73 in Africa and Madagascar of which c. 15 extend to Asia, 21 restricted to Asia, 7 in Australia and the Pacific; c. 60 spp. in the New World, of which c. 35 in N and C America and c. 25 in S America); Senegalia (syn.: Acacia subg. Aculeiferum sens.strict.), c. 207 spp., pantropical (69 in Africa and Madagascar, of which 7 extend to Asia, 36 restricted to Asia, 2 in Australia and the Pacific [1 extending to Asia]; c. 100 New World of which c. 40 in N and C America, c. 60 in S. America); Acaciella (syn.: Acacia subg. Aculeiferum sect. Filicinae), 15 spp. restricted to the Neotropics (mainly Mexico and C America but extending thinly to S America); Gen nov. (the 'Acacia coulteri' group), 13 spp. restricted to N and C America; 'Racosperma' (syn.: Acacia subg. Phyllodineae), c. 1045 spp. in Australia (of which 941 endemic and 7 extending to Asia, and c. 100 spp. new and yet to be described fide Maslin et al., 2003), 7 in the Pacific, 3 confined to Asia, 2 in Madagascar and the Mascarenes

[FSOM]
Use
Several Australian Acacia species with phyllodic leaves have been planted on dunes particularly in S Somalia in recent years.

[LOWO]
Use
Leaves, fruits, wood and bark of many species are used for livestock fodder (although pods and leaves of some yield toxic cyanogenic glycosides), timber (construction, handicrafts, utensils, implements), famine food, firewood, charcoal, medicine, tanning leather (e.g., A. mearnsii De Wild., black wattle ) and oils in aromatherapy; many species important in agroforestry systems (e.g., A. mangium Willd., mangium or brown salwood , grown widely as a plantation species in Asia); some species planted as ornamentals, cut flowers of A.dealbata Link and a few other species are sold as 'florists' mimosa' ; many species are good bee forage; flowers of A. farnesiana (L.) Willd. are used in the perfume industry; several species a major source of gum arabic although A. senegal (L.) Willd. is the 'true gum arabic' ; many African species are multi-purpose trees with a wide range of local uses (see Burkill, 1995: 177-203); in Australia used in rehabilitation and soil improvement programmes, waterproof glue production, pulp, for tools, aboriginal weapons and musical instruments; seeds have minor use as human food

Native to:

Borneo, Fiji, Hawaii, Jawa, Lesser Sunda Is., Madagascar, Malaya, Maluku, Mauritius, New Caledonia, New Guinea, New Guinea, New South Wales, Northern Territory, Philippines, Queensland, Réunion, Samoa, Solomon Is., South Australia, Sumatera, Taiwan, Tasmania, Tonga, Vanuatu, Victoria, Wallis-Futuna Is., Western Australia

Introduced into:

Albania, Algeria, Amsterdam-St.Paul Is, Andaman Is., Angola, Argentina Northeast, Ascension, Assam, Azores, Bahamas, Bangladesh, Benin, Bolivia, Brazil Northeast, Brazil South, Brazil Southeast, Burkina, California, Cambodia, Cameroon, Canary Is., Cape Provinces, Cape Verde, Caroline Is., Chile Central, Chile North, Chile South, China South-Central, China Southeast, Colombia, Comoros, Cook Is., Corse, Costa Rica, Cuba, Cyprus, Desventurados Is., Dominican Republic, East Aegean Is., East Himalaya, Easter Is., Ecuador, El Salvador, Eritrea, Ethiopia, Florida, France, Free State, Great Britain, Greece, Guatemala, Guinea, Hainan, Haiti, Honduras, India, Iraq, Italy, Jamaica, Juan Fernández Is., Kenya, Kriti, KwaZulu-Natal, Laos, Lebanon-Syria, Leeward Is., Lesotho, Libya, Madeira, Malawi, Marianas, Mexico Southwest, Morocco, Mozambique, Myanmar, Namibia, Nansei-shoto, Nepal, New Zealand North, New Zealand South, Nicaragua, Nicobar Is., Nigeria, Norfolk Is., North Caucasus, Northern Provinces, Ogasawara-shoto, Oman, Oregon, Pakistan, Palestine, Panamá, Peru, Portugal, Puerto Rico, Romania, Rwanda, Sardegna, Saudi Arabia, Seychelles, Sicilia, Somalia, Spain, Sri Lanka, St.Helena, Sudan, Swaziland, Tanzania, Tokelau-Manihiki, Transcaucasus, Trinidad-Tobago, Tuamotu, Tunisia, Turkey, Uganda, Ukraine, Uruguay, Venezuela, Vietnam, West Himalaya, Yemen, Yugoslavia, Zambia, Zaïre, Zimbabwe

Acacia Mill. appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Bally, P.R.O. [B14409], Kenya 2700.048
Pennington, R.T. [154], Bolivia 29047.762
Passos, L. [39], Bahia K000850959
Hoehne, W. [s.n.], São Paulo K000868478
Rico, L. [1960], Dominican Republic 77450.000
Hoehne, W. [s.n.], São Paulo K000868477

First published in Gard. Dict. Abr. ed. 4: s.p. (1754)

Accepted by

  • Govaerts, R. (1995). World Checklist of Seed Plants 1(1, 2): 1-483, 529. MIM, Deurne.

Literature

Flora of West Tropical Africa

  • Benth. in Trans. Linn. Soc. 30: 444 (1875).
  • —F.T.A. 2: 337

Flora Zambesiaca

  • Gard. Dict., abridg. ed. 4 (1754)

Flora of Somalia

  • Brenan in Fl. Trop. E. Afr. (1959)
  • Flora Somalia, Vol 1, (1993) Author: by M. Thulin, A. S. Hassan & B. T. Styles [updated by M. Thulin 2008]
  • Hassan & Styles, A conspectus of Somali Acacias (1990).
  • Ross in Mem. Bot. Surv. S. Afr. 44 (1979)

Flora of Tropical East Africa

  • Gard. Dict., abridg. ed.: 4 (1754)

  • Art and Illustrations in Digifolia

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  • Flora Zambesiaca

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  • Flora of Somalia

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  • Flora of Tropical East Africa

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  • Herbarium Catalogue Specimens

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    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
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  • Kew Names and Taxonomic Backbone

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  • Legumes of the World Online

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  • Plants and People Africa

    Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
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