Authors: Karan Rawlins, Hillery Reeves and Kaylee Tillery at the Center for Invasive Species & Ecosystem Health, University of Georgia
- Acacia confusa is a small many branched tree or shrub in the family Fabaceae. It is native to Australia, Indonesia, and Papua New Guinea. Acacia confusa grows up to 13 ft. (4 m) tall and 3.3 ft. (1 m) in diameter. It bears straight stipular thorns.
- The foliage on mature Acacia confusa are usually falcate phyllodes. They are alternate and have a leathery texture. Leaves have parallel curving veins. They range from 3-4 in. (8-10 cm) long and are narrowed at both ends. Foliage on juvenile Acacia confusa are usually of bipinnate with 4-8 pairs of pinnae. Each pinnae has 10-12 pairs of small asymmetric leaflets.
- Acacia confusa flowers are small, rounded, yellow heads ranging from 0.23-0.3 in. (6-8 mm) in diameter. 1 to 3 flowers heads can be found in the axil of the phyllode. Acacia confusa flowers are fragrant and have numerous stamens.
- The fruit of Acacia confusa are pods that each contain about 8 brown, compressed, elliptic seeds. Fruit pods are dark brown to black. They range from to 3 in. (8 cm) long, to 0.5 in. (12 mm) wide. The pods are plump and usually slightly curved or twisted.
- Ecological Threat
- Acacia confusa can form monocultures and it has proven to be an invasive problem in some islands after introduction.
Acacia confusa is native to Australia, Indonesia, and Papua New Guinea. It has become invasive on many of the islands where it has been introduced. Acacia confusa has been introduced to Hawaii, Guam, Japan and Indonesia. It has also been introduced to Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Palau, Peninsular Malaysia, Mauritius, and Seychelles.
Acacia confusa can form monocultures. br />
- Small seedlings can be hand-pulled, especially when the soil is moist.
- Larger plants and their root systems can be dug out with a spading fork or pulled with a weed wrench.
- Mature trees can be cut. The stump must be ground out or the re-growth clipped.
- Apply 20% triclopyr ester produt in oil to the cut-stump. 5% triclopyr ester product in diesel oil applied to the basal bark also effective. Triclopyr at 2 lb/acre in foliar applications provided 80% control in field trials. Always follow label directions. Other chemicals produced unsatisfactory results.
- No biocontrol information available.
- Prescribed fire is not recommended. Fire can trigger very high germination rates in seed present in the soil.
- Introductions to islands where it is not already present is not recommended.
Images from Bugwood.org