Species numbers

The essay below was prepared in 2004 and provides information then available on Acacia worldwide and on the Australian species.

More comprehensive and current information concerning Acacia species numbers is now provided elsewhere on WorldWideWattle.

The genus worldwide

In terms of species numbers Acacia, as currently defined, is the second largest genus in the Pea family (i.e. the Leguminosae) (Astragalus is the largest).

This cosmopolitan genus contains in excess of 1380 species. This is a conservative number as it does not include many of the undescribed taxa (an estimated 100+ species in Australia and 20 species in the Americas, fide Maslin et al. 2003). Acacias grow in tropical, subtropical and warm temperate parts of the world and are found in the African region (144 species), Asia (89 species), the Americas (about 185 species) and the Australian region (993 species).

The current classification recognizes five major groups within Acacia, namely, subgenus Acacia (about 163 currently accepted, described species), subgenus Aculeiferum sens. str. (203 currently accepted, described species), subgenus Phyllodineae (987 currently accepted, described species), section Filicinae (15 currently accepted, described species) and the ‘Acacia coulteri’ group (13 currently accepted, described species).Following the impending split of Acacia each of these groups is likely to be treated as a distinct genus.

Note: Species numbers given on these pages here been updated subsequent to the publication of numbers that are cited in Maslin et al. (2003) and Orchard & Maslin (2003).

Table 1. Numbers of accepted, described species of Acacia sens. lat. worldwide (following Maslin et al. 2003 but species numbers modified in accordance with Table 3 below)

Taxonomic group1	Americas	Africa2	Asia	Australia & Pacific	Total no. of spp
Subgenus Acacia (Acacia; syn. Vachellia)	c. 60	73	36 (incl. c. 15 also found in Africa)	9	c. 163
Subgenus Aculeiferum sens. str. (Senegalia)	97	69	43 (incl. 7 also found in Africa)	2 (incl. 1 also found in Asia)	203
Section Filicinae (Acaciella)	15	-	-	-	15
‘Acacia coulteri’ group (a new genus)	13	-	-	-	13
Subgenus Phyllodineae (Racosperma’)	-	23	10 (incl. 7 also found in Australia)	9824	987
Total number of species	c. 185	144	89 (incl. c. 29 occurring also outside the region)	993 (incl. 1 also found in Asia)	1381

¹ The generic names given in parentheses in this column are those that would apply by the application of currently designated types; this issue is discussed elsewhere on WorldWideWattle.

²Includes Madagascar, Reunion and Mauritius.

³2 species in Madagascar, Reunion and Mauritius. (Note: Du Puy & Villiers 2002 consider that only one species of this group occurs in this region).

⁴975 species in Australia (see Table 3 below); 7 species in the Pacific.

The above species numbers are derived from the following sources:

Subgenus Acacia

• Americas — Ebinger et al. (2000) and Clarke et al. (2000).
• Africa — Ross (1979), Lock (1989), Boulos (1995), Thulin & Hassan (1996), Thulin (1998) and Du Puy & Villiers (2002).
• Asia — Ali (1973), Nielsen (1992), Thothathri (1992), Lock & Simpson (1991), Lock & Heald (1994), Kumar & Sane (unpubl. data) and Seigler (unpubl. data).
• Australia — see Table 3 below.

Subgenus Aculeiferum sens. str.

• Americas — Seigler (unpubl. data).
• Africa — Ross (1979), Thulin & Tardelli (1988), Lock (1989), Thulin (1989), Thulin & Hassan (1990) and Du Puy & Villiers (2002).
• Asia — Ali (1973), Lock & Simpson (1991), Nielsen (1992), Lock & Heald (1994), Kumar & Sane (unpubl. data) and Seigler (unpubl. data).
• Australia — see Table 3 below.

Section Filicinae

• Americas — L. Rico Arce (pers. comm.)

Acacia coulteri group

• Americas — Jawad et al. (2000)

Subgenus Phyllodineae

• Africa (Madascar & Mascarenes) — Pedley (1975) and Du Puy & Villiers (2001).
• Asia — Pedley (1975) and Howcroft (1987: A. pubirhachis in Papua New Guinea).
• Australia & Pacfic — See Table 3 below (Australia) and Pedley (1975, Pacific).

Numbers of Australian species

Within Australia there are 986 currently accepted, described species of Acacia, but this number increases to 1023 when naturalised and some informal species are included (see Table 3 below). There are 6 naturalised Acacias in Australia (A. farnesiana is included in this total as it is considered to be probably a pre-European introduction to the continent). It is estimated that there are around 100 additional species yet to be described from this region.

Most of the 1023 species of Acacia in Australia (comprising 1166 described, informal and naturalised taxa, see Table 2) are described in the electronic publication WATTLE (Maslin 2001). Taxa not included in WATTLE but which have been described subsequently, appear in Bartolome et al. (2002). WATTLE also includes a few taxa which at the time were undescribed but have since been formally published in the Appendix to the Flora of Australia vol. 11B (Orchard & Wilson 2001), Kodela (2001), Kodela & Tindale (2001), O’Leary (2002 & 2002a), O’Leary & Maslin (2002), Pedley (2002) and McDonald (2003).

The majority (almost 99%) of the Australian Acacias are contained in subg. Phyllodineae with only 19 species of this group occurring outside the continent: these are found in the Pacific region east to Hawaii (7 species), Asia north to the Philippines (3 species) and Madagascar & the Mascarene Is. in the Indian Ocean off the east coast of Africa (2 species).Seven of these species also occur in Australia.The extra-Australian species, except A. sericoflora (which occurs in Papua-New Guinea), are detailed in Pedley (1975).

Table 2. Numbers of Acacia taxa and species in Australian and its States and Territories (information from Maslin 2001 and relevant subsequent publications)

Region	Number of taxa	Number of species1
		Total	Native	Naturalised (incl. A. farnesiana)
Australia	1166	1023	1017	6
Western Australia	712	599	587	12 (including 1 probable naturalised)
Queensland	307	286	277	9
New South Wales	264	241	238	3
Northern Territory	197	180	177	3
South Australia	154	137	128	9
Victoria	131	114	107	7 (including 1 probable naturalised)
Australian Capital Territory	34	32	30	2 (including 1 possibly naturalised)
Tasmania	30	26		6 (including 2 probable naturalised)

¹Includes described species and some undescribed & hybrid species (see Australian taxa list).

Table 3. Numbers of Australian Acacia species in each of the major infrageneric groups (numbers taken from Maslin 2001 and relevant subsequent publications: see Australian taxa list)

Infrageneric group	Native, accepted, described species	Naturalised species	Undescribed/dubious/hybrid species	Total no. of species
Subgenus Acacia	9	2 (incl. A. farnesiana	1 dubious	12
Subgenus Aculeiferum	2	4		6
Subgenus Phyllodineae	[975]		[30 (24 undescribed, 2 dubious, 4 hybrid)]	[1005]
Section Phyllodineae	397		14 (10 undescribed, 2 hybrid, 2 dubious)	411
Section Juliflorae	255		8 (6 undescribed, 2 hybrid)	263
Section Plurinerves	216		6 undescribed	222
Section Botrycephalae	40		2 undescribed	42
Section Pulchellae	26			26
Section Alatae	23			23
Section Lycopodiifoliae	18			18
TOTALS	986	6 (incl. A. farnesiana)	31 (24 undescribed, 3 dubious, 4 hybrid)	1023

The patterns of distribution of these species across the continent are shown elsewhere on WorldWideWattle.

Lists of Australian taxa of Acacia

• Australia
• Australian Capital Territory
• New South Wales
• Northern Territory
• Queensland
• South Australia
• Tasmania
• Victoria
• Western Australia

References

Ali, S.I. (1973). Mimosaceae.In ‘Flora of West Pakistan, No. 36’. (Eds E. Nasir and S.I. Ali) pp. 1-41. (Department of Botany, University of Karachi: Karachi.)

Bartolome, M., Walsh, N.G., James, E.A. and Ladiges, P.Y. (2002). A new, rare species of Acacia from north-eastern Victoria. Australian Systematic Botany 15: 465-475.

Boulos L .(1995). Notes on Acacia Mill.Studies in the Leguminosae of Arabia: 1. Kew Bulletin 50: 327-337.

Clarke, H.D., Downie, S.R. and Seigler, D.S. (2000). Implications of chloroplast DNA restriction site variation for systematics of Acacia (Fabaceae:Mimosoideae). Systematic Botany 25: 618-632.

Du Puy, D. and Villiers, J.F. (2002). Acacia.In ‘The Leguminosae of Madagascar’. (Eds D.J. Du Puy, J.N. Labat, R. Rabevohitra, J.F. Villiers, J. Bosser and J. Moat ) pp. 750.(Royal Botanic Gardens, Kew: London.)

Ebinger, J.E., Seigler, D.S. & Clarke, H.D. (2000). Taxonomic revision of South American species of the genus Acacia subgenus Acacia (Fabaceae: Mimosoideae). Systematic Botany 24(3): 588-617.

Howcroft, N.S. (1987). Seed collections of Acacias carried out in 1986 in Western Province, Papua New Guinea. Forest Genetic Resources Information (FAO) 16: 14-16.

Jawad, J.T., Seigler, D.S. and Ebinger, J.E. (2000). A systematic treatment of Acacia coulteri (Fabaceae, Mimosoideae) and similar species in the New World. Annals of the Missouri Botanical Garden 87: 528-548.

Kodela, P.G. (2001). Acacia atrox (Fabaceae: Mimosoideae), a new rare species from the North Western Slopes, New South Wales. Telopea 9: 415-419.

Kodela P.G. and Tindale M.D. (2001). Acacia dealbata subsp. subalpina (Fabaceae: Mimosoideae), a new subspecies from south-eastern Australia. Telopea 9: 319-322.

Lock, J.M. (1989). ‘Legumes of Africa, a check-list.’ (Royal Botanic Gardens Kew: London.)

Lock, J.M. and Heald, J. (1994). ‘Legumes of Indo-China, a check-list.’ (Royal Botanic Gardens Kew: London.)

Lock, J.M. and Simpson, K. (1991). ‘Legumes of West Asia, a check-list.’ (Royal Botanic Gardens Kew: London.)

Maslin, B.R. (coordinator) (2001). WATTLE Acacias of Australia. CD ROM Publication. (Published by Australian Biological Resources Study, Canberra and Department of Conservation and Land Management, Perth).

Maslin, B.R., Miller, J.T. and Seigler, D.S. (2003). Overview of the generic status of Acacia (Leguminosae: Mimosoideae). Australian Systematic Botany 16(1): 1–18. An abstract of this paper (together with a provision to purchase the whole article) is available from CSIRO Publishing.

McDonald, M.W. (2003). Revision of Acacia tumida (Leguminaosae: Mimosoideae) and close allies, including the description of three rare taxa. Australian Systematic Botany 16: 139-164.

Nielsen, I.C. (1992). Acacia.‘Flora Malesiana’ ser. I, 11: 34-64.

O’Leary, M.C. (2002). Acacia spooneri (Leguminosae: Mimosoideae: sect. Phyllodineae), a new species from the Flinders Ranges, South Australia. Journal of the Adelaide Botanic Gardens 20: 11-15.

O’Leary, M.C. (2002a). Acacia toondulya (Leguminosae: Mimosoideae: sect. Phyllodineae), a new species from Eyre Peninsula, South Australia. Journal of the Adelaide Botanic Gardens 20: 17-20.

O’Leary, M.C. and Maslin, B.R. (2002). Acacia simmonsiana Leguminosae: Mimosoideae: sect. Phyllodineae, a new species from south-eastern Australia. Journal of the Adelaide Botanic Gardens 20: 5-10.

Orchard, A.E. and Maslin, B.R. (2003). Proposal to conserve the name Acacia (Leguminosae: Mimosoideae) with a conserved type. Taxon 52(2): 362–363. A web download of this paper is available.

Orchard, A.E. and Wilson, A.J.G. (2001) (eds). Flora of Australia Volume 11B, Mimosaceae, Acacia part 2. (ABRS/CSIRO Publishing: Melbourne.)

Pedley, L. (1975). Revision of the extra-Australian species of Acacia subg. Heterophyllum. Contributions from the Queensland Herbarium 18: 1-24.

Pedley, L. (2002). A conspectus of Acacia subg. Acacia in Australia. Austrobaileya 6: 177-186.

Ross, J. (1979). A conspectus of the African Acacia species. Memoirs of the Botanical Survey of South Africa 44: 1-155.

Thothathri, K. (1992). Nomenclatural note on Acacia minutifolia Ragu. et al. from India. Rheedea 2: 73.

Thulin, M. (1989). New or noteworthy species of Leguminosae in NE tropical Africa. Nordic Journal of Botany 8: 457-488.

Thulin, M. (1998). Two new species of Acacia (Leguminosae) from north-eastern Somalia. Nordic Journal of Botany 18: 513-517.

Thulin, M. and Hassan, A.S. (1990). Acacia ochracea (Leguminosae-Mimosoideae), a new species from Somalia. Nordic Journal of Botany 10: 477-479.

Thulin, M. and Hassan, A.S. (1996). A new species of Acacia (Leguminosae) from the Horn of Africa. Nordic Journal of Botany 16: 303-306.

Thulin, M. and Tardelli, M. (1988). A new species of Acacia (Leguminosae, Mimosoideae) from Somalia. Willdenowia 17: 125-128.

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