Acacia implexa

Acacia implexa Benth.

Common names: Screw-pod wattle, Lightwood, Hickory wattleFamily name: Fabaceae Category: proposed 1a NEMBA Description

Erect tree to 15m tall, single-stemmed or divided near ground level into 2 or 3 main stems. Leaves dark green, narrowly-elliptic and sickle shaped, 7-20 cm long and 6-25 mm wide, much narrowed at the base. Bi-pinnate leaves may persist on young plants. Bark rough and greyish. Flowers arranged in globular heads, creamy to pale yellow, flowering from December to March. Pods narrow, coiled and twisted to 25 cm long, 4-7 mm wide. Seeds dark brown, longitudinal, fleshy tissue growing from the point of attachment of a seed.

DistributionScrew-pod wattle is native in Eastern Australia, China, Europe, India and the U.S.A. History in South AfricaAcacia implexa has been recorded in the Western Cape at Tokai forest, Stellenbosch and Wolseley. Environmental and economic impact Screw-pod wattle is a fast growing tree and invades agricultural lands, planted forest and disturbed areas. It can become highly invasive if not controlled. How it spreads Screw-pod wattle spreads through suckers (side shoots or underground runners generate at the base of the tree). How to eradicate Currently control is by uprooting the plant. There are no herbicides registered for this species in South Africa. References

• Australia National Heritage Trust. Acacia implexa. Available on http://thebegavalley.org.au/uploads/media/Lightwood_or_Hickory.pdf
• Eradication and monitoring of Australian acacias in South Africa s part of Early Detection and Rapid Response Program. Available on: http://archives.eppo.org/MEETINGS/2010_conferences/ias_trabzon/22_Wilson.pdf
• South African Plant Atlas. ARC-Plant Protection Research Institute. available on line http://www.dargleconservancy.org.za/documents/sapia08.pdf
• South African plants invaders atlas database. ARC- Plant protection research institute, Pretoria, South Africa. Available on: www.agis.agric.za