Acacia paradoxa

Acacia paradoxa DC

Common names: kangaroo thorn, prickly wattle or hedge wattleFamily name: FabeceaeCategory: proposed 1 NEMBA

Description Thorny shrub 4 m tall. Leaves dark green, narrow elliptic 3cm long, prominent midveins and marginal veins. Bark cracked, brownish grey. Flowers yellow to bright yellow appearing from September to October. Seeds longitudinally, small fleshy structures called alaiosomes. Pods brown, hairy and straight raised over seeds.

DistributionKangaroo thorn is native in Australia. It is naturalised in the United states. History in South AfricaIt is not clear how kangaroo thorn was introduced in South Africa, but the earliest record is of a specimen lodged in the Bolus Herbarium at the University of Cape Town in 1937.  Environmental and economic impactKangaroo thorn invades exposed erosion slopes, valley, pine plantation, agricultural lands and fynbos. The dense growth of kangaroo thorn may potentially reduce the abundance of native species. The seeds tolerate diverse environmental conditions and have the potential to colonize the land. How it spreadsThe kangaroo thorn spreads by seeds, which are dispersed by ants. How to eradicateCurrently there are no herbicides registered for kangaroo thorn in South Africa. It can be controlled by uprooting. What can you do to help?Report sightings of these plants to the Early Detection and Rapid Response Programme (EDRR) at SANBI. We will need to know its locality (the exact locality, supply any landmarks or GPS information if possible).

Contact detailsKanyisa JamaEmail address: alienplants@sanbi.org.za Tel: 021 799 8762

References

• Zenni, R.D. Wilson, J.R.U., Le Roux J.J. andRicherdson, D.M. .2009. Evaluating the invasiveness of Acacia paradoxa in South Africa. South African Journal of Botany 75: 485-496.Available online at www.sciencedirect.com
• Moore,J. L. M. C. Runge, B. L. Webber and J. R. U. Wilson. 2011. Contain or eradicate? Optimizing the management goal for Australian acacia invasions in the face of uncertainty. Journal of Conservation Biogeography 17:1047-1059. Available online at http://onlinelibrary.willey.com/doi/10.1111/j.1472-4642.2011.00809.x/pdf
• South African plants invaders atlas database. ARC - Plant protection research institute, Pretoria, South Africa. Available on: www.agis.agric.za
• Wilson, J. R. U., Kaplan, H., Mazibuko, D., De Smith, J., Zenni, R. D. and Van Wyk, E. 2010. Eradication and monitoring of Australian acacias in South Africa as part of Early Detection and Rapid Response Program. Available on: http://archives.eppo.org/MEETINGS/2010_conferences/ias_trabzon/22_Wilson.pdf

See more on invasive alien plants and their categories

Prepared by Buhle Mthembu

September 2011