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.
(
click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Acacia atrox
Gazetted date:
30 Jun 2001
Profile last updated:
14 Oct 2024
Description
Myall Creek Wattle is a dense shrub 0.5 - 6 m tall with creamy or pale yellow flowers and a twisted green-brown stem. The entire plant is covered in light green to blue-green spines (leaves), 2 - 4 cm long and 1 - 1.2 mm wide. It flowers sporadically throughout the year, with flowers clustered into ball-shaped heads and paired flower heads on each stem. However, no pods and seeds have ever been seen, with the only vegetative spread recorded being through root suckers. This wattle was first discovered in 2000 and spread of the species outside of known patches has been extremely slow since then. Acacia atrox subsp. planitiicola has an apparently more tree-like form than the type subsp, but slow recovery of the latter after nearly all mature stems were destroyed may eventually prove them to be similar. May be closely related to Acacia carneorum.
Distribution
Myall Creek Wattle is known from two populations near Delungra and Gurley. Each population occupies less than 5 hectares. Individuals on Kirramingly Nature Reserve have been described as a separate subspecies Acacia atrox subsp. planitiicola (formerly planiticola),of which six small patches exist. The distribution, ecology and failure of each subspecies to form seed pods suggests the species was once very widely distributed in the region.
Habitat and ecology
- Myall Creek wattle grows in soils ranging from deep black clay over basalt to shallow red stony loams on the upper slope and crest of a low hill. The type subsp. occurs in a partly cleared paddock in box woodland with a native grassy understorey. A. a. planitiicola exists on a plain of basalt-derived cracking clay loam. This latter subsp is spread in six discrete patches which are not vegetatively connected now. Genetic analysis and phenotypic comparisons suggest the patches derived from two similar individuals.
- The type subspecies population currently comprises mostly young stems, with several individuals showing old growth characteristics indicating longevity of a stem may be many decades. A. a. planitiicola comprises about 250 stems, many of which are more tree-like than the current population of the type subsp. Little recruitment is apparent at this latter site, and most new stems arise where soil disturbance occurs above a root (e.g. kangaroo beds).
- Uniquely shaped hard galls, reminiscent of Hakea fruit, form in the thorns of both subspecies. The recent discovery on the wattle of a lepidopteran cocoon which was shaped identically to these galls suggests the plant has an exceedingly long evolutionary history.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Clearing of habitat for agriculture and pasture improvement where protection has not been implemented or the species is not recognised.
- Frequent or intense fires. As the Myall Creek Wattle apparently survives only through suckering from roots, fire can destroy demographic structure and potentially kill the entire 'individual' if severe.
- Trampling by domestic stock can destroy young stems and break the stems of medium-sized individuals.
- The very small, restricted population makes the species vulnerable to chance events and disease.
Recovery strategies
A targeted strategy for managing this species has been developed under the Saving Our Species program; click
here for details. For more information on the Saving Our Species program click
here
Activities to assist this species
- Protect known populations frequent fire.
- Protect known populations from excessive trampling by stock.
- Protect newly discovered populations from clearing and pasture improvement.
- Report new records of Myall Creek wattle to the OEH.
Information sources
- Copeland, L.M. and Kodela, P.G. (2012) Acacia atrox subsp. planiticola (Fabaceae: Mimosoideae), a new threatened subspecies from the North Western Plains of New South Wales, Australia. Telopea 14: 63-68.
- Hunter, J.T. (2002) A preliminary overview of what is reserved in the Inverell and Yallaroi Shires, North Western Slopes, NSW. Cunninghamia 7(4): 671–681
- Kodela, P.G. (2001) Acacia atrox (Fabaceae: Mimosoideae), a new rare species from the North Western Slopes, New South Wales. Telopea 9(2): 415-419.
- 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)
- NSW National Parks and Wildlife Service (2003) Threatened Species of the New England Tablelands and North West Slopes of NSW. (NSW NPWS, Coffs Harbour)
- NSW Scientific Committee (2001) Acacia atrox (a tall shrub) - Endangered species determination - final.
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IBRA Bioregion
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IBRA Subregion
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Known or predicted
|
Geographic restrictions region
|
|---|
| Nandewar | Inverell Basalts |
Predicted
| Within 30 km of Myall Creek |
| Nandewar | Peel |
Known
| None |