Indicative distribution
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas.
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The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Acacia acanthoclada
Profile last updated:
05 Oct 2023
Description
Acacia acanthoclada was first described as a rigid, divaricate and spinescent shrub with small rigid phyllodes which are narrow-cuneate and slightly notched at the apex. The Flora of NSW describes Acacia acanthoclada as an erect or spreading shrub, 0.3-1.5 m high; bark smooth, grey or occasionally slightly greenish; branchlets ± terete, spinose, densely hairy. Phyllodes ± straight, 0.2-0.6 cm long, 1-2 mm wide, midvein prominent, lateral veins sometimes conspicuous, apex acute to obtuse with a mucro, hairy; glands absent; pulvinus < 2 mm long. Heads 20-35-flowered, golden yellow, 1 in axil of phyllodes; peduncle 2-8 mm long. Pod twisted or coiled, ± flat, 3-6 cm long, 3-6 mm wide, brown, glaucous; seeds longitudinal; funicle expanded towards seed. In western NSW, Acacia acanthoclada plants are also described as low rigid shrubs with downy whitish branches and hard spiny branchlets. Two subspecies have been described, but only the nominate (acanthoclada) occurs in NSW.
Distribution
The Harrow Wattle occurs across southern Australia, with the nominate subspecies occurring sporadically in south west NSW and far north west Victoria and more frequently in South Australia and southern Western Australia. The other subspecies (glaucescens) is restricted to the last state. Most records in NSW are either in the Scotia mallee (Scotia Sanctuary and adjoining properties) or from an area to the north east of Buronga (the area between Mallee Cliffs and Mungo National Parks but not within either of these reserves). Some of these sites occur within Southern Mallee Reserves on leasehold land which stock grazing excluded. A single (dead) plant has also recently been recorded west of Lake Victoria, so additional survey may expand the number of known populations in south western NSW.
Habitat and ecology
- Grows in mallee communities on ridges and dunes and very occasionally on rocky outcrops; generally grows in deep, loose, sandy soil.
- Associated species include White Mallee (Eucalyptus dumosa), Red Mallee (E. socialis), Yorrell (E. gracilis), Ridge-fruited Mallee (E. costata subsp. murrayana), Mallee Pine (Callitris verrucosa), Native Poplar (Codonocarpus cotinifolius) and Porcupine Grass (Triodia scariosa subsp. scariosa).
- Flowers from August to October.
- Grows from seed, requiring a warm, well-drained position in full sun or a little shade; grows well in well-drained sandy or loamy soils but will tolerate some clay and is considered to be quite long-lived as plants can be very deeply rooted.
- Plants have been recorded in or adjacent to areas regenerating after fire.
- One population on leasehold land is three to four hectares in area and comprises stunted and very woody plants, while another recently surveyed population found thousands of plants scattered over several hectares, most of which were dead with the rest heavily grazed (probably by goats). Plants have also been noted as scattered, occasional and very sparse within other populations.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Clearing is a major threat, with many populations located near roads and in mallee areas that are being cleared.
- Many populations appear to be suffering from overgrazing, mainly from goats but potentially also domestic stock and kangaroos.
- Lack of knowledge and information about this species' ecology, particularly seedling recruitment, life cycle and lifespan.
- Fire appears to play a role in the ecology of this species, with some populations associated with fire scars. Changes in fire regime may influence the distribution of this species.
- Small population size with very few plants exist on lands managed for conservation.
- Uncertainty about extent and severity of goat and / or fire regime threats.
Recovery strategies
Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological
community. The Office of Environment and Heritage has identified
9 priority actions
to help recover the Harrow Wattle in New South Wales.
Activities to assist this species
- The exact requirements of this species are not known, but it appears to germinate in response to fire. Mosaic burning of appropriate habitat on a 10 to 40 year cycle with monitoring to indicate timing for the next burn. No more than 5% of the area should be burnt in a single year, and no more than 15% in 5 years. Following occurrence of wildfire, monitoring required prior to additional ecological burns.
- Protect from feral and domestic herbivore grazing, and investigate the impacts of kangaroo grazing.
- Undertake investigations into regeneration, including seed-set, germination and seedling survival, as well as the impacts of fire and grazing.
- Baseline surveys are required to confirm known populations and locate new ones.
Information sources
- Ayers, D., Nash, S. and Baggett, K. (1996) Threatened Species of Western New South Wales. (NSW National Parks and Wildlife Service, Sydney)
- Bentham, G. (1863) Flora Australiensis. Volume 2 (1864). (Reeve, London)
- Bowen, P.F. and Pressey, R.L. (1993) Localities and habitats of plants with restricted distributions in the Western Division of New South Wales. Occasional Paper No. 17. (NSW NPWS, Sydney)
- Briggs, J.D. and Leigh, J.H. (1996) Rare or Threatened Australian Plants. Revised Edition. (CSIRO Publishing, Melbourne)
- Clements, A., Rodd, T., Moore, R.J., Crane, A.G. and Simpson, J. (2000) Surveys of areas having potentially high botanical diversity near Pooncarie, South Far Western Plains. Cunninghamia 6(3): 611-643.
- Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992) Plants of Western New South Wales. (Inkata Press, Sydney)
- Hall, N. and Johnson, L.A.S. (1993) The names of acacias of New South Wales - with a guide to pronunciation of botanical names. (Royal Botanic Gardens, Sydney)
- Kodela, P.G. and Harden, G.J. (2002) Acacia. Pp 381-476 in Harden, G.J. (ed.) Flora of New South Wales. Volume 2. Revised Edition (New South Wales University Press, Sydney)
- Maslin, B.R. and Pedley, L. (1982) The distribution of Acacia (Leguminosae: Mimosoideae) in Australia. Part 1. Species distribution maps. Western Australian Herbarium Research Notes 6: 1-128.
- Mueller, F.J.H. von (1863) Acacia acanthoclada F. Muell. Fragmenta Phytographiae Australia 3: 127.
- Porteners, M. and Robertson, G. (2003) Threatened Plants in Western New South Wales: Information Review. (NSW NPWS, Hurstville)
- Porteners, M.F. (1998) Tarawi Nature Reserve Threatened Plants Survey. Report to the NSW National Parks and Wildlife Service (NSW NPWS, Sydney)
- Pressey, R.L., Cohn, J.S. and Porter, J.L. (1990) Vascular plants with restricted distributions in the Western Division of New South Wales. Proceedings of the Linnean Society of New South Wales 112: 213-227
- Simmons, M.H. (1981) Acacias of Australia. (Nelson, Melbourne)
- Walsh, N.G. and Entwisle, T.J. (1998) Flora of Victoria; Volume 3, Dicotyledons Winteraceae to Myrtaceae. (Inkata Press, Melbourne)
- Westbrooke, M.E., Miller, J.D. and Kerr, M.K.C. (1998) The vegetation of the Scotia 1:100 000 map sheet, western New South Wales. Cunninghamia 5(3): 665-684
- Whibley, D.J.E. and Symon, D.E. (1992) Acacias of South Australia. Revised Second Edition. (South Australian Government, Adelaide)
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