Acacia aneura (mulga) is a shrub or small tree that is native to arid and semi-arid regions of Australia. It is used as a source of fodder and timber and has been introduced to a number of locations worldwide, including the Hawaiian Islands. It is now reported to be naturalized on the island of Lanai. In its native range, it forms dense stands, is able to reproduce through facultative apomixis, and periodically produces large numbers of seeds after exceptionally high rainfall years.
High Risk Traits:
- Able to grow and spread in arid to semi-arid tropical regions.
- Naturalized on Lanai (Hawaiian Islands)
- Identified as a potential environmental weed by botanists in the Hawaiian Islands.
- Other Acacia species are invasive weeds.
- May be toxic to sheep if eaten (limited evidence).
- Might increase fire risk in fire prone ecosystems (but lower risk than flammable grasslands).
- Tolerates many soil types.
- Forms dense stands in native range.
- N-Fixing species (modifies soil nutrient levels and may facilitate establishment of other weeds).
- Reproduces by seeds.
- Hybridizes with other Acacia species.
- Can reproduced through facultative apomixis.
- Seeds dispersed by ants, gravity, potentially birds and water, and through intentional cultivation.
- Prolific seed production following heavy rainfall years.
- Seeds may form a persistent seedbank (>1 year).
Low Risk Traits:
- Palatable to grazing animals
- Unarmed (no spines, thorns, or burrs)
- Grows best in full sun and high light environments (dense shade may inhibit spread)
- Not documented to spread vegetatively.
- Slow growing and reaches reproductive maturity in 10+ years.
- Limited seed production in years with low precipitation.
- Killed by cutting and fire.