Also known as
Prickly-leaved wattle, star-leaved acacia, prickly mimosa, whorl-leaved acacia
Where is it originally from?
What does it look like?
Evergreen, long lived (20-30 years), perennial shrub or small tree with ribbed, hairy twigs. Leaves reduced to flattened, spiked leaf stalks (<17 mm x 4 mm). Solitary, pale yellow flowers grouped on flower heads (Sep-Nov) that extend beyond the leaves develop into seeds contained in usually straight pods (<100 mm x 4 mm) that can be slightly hairy. Stems often covered with fungi-induced galls.
Why is it weedy?
Fixes nitrogen, giving it the competitive advantage in poor soil condions. Spines on the branches of the tree discourage mammalian browsers such as possums.
It cannot grow in the shade, but can tolerate exposed coastal conditions. Fire or soil disturbance encourages germination of long-lived seeds.
How does it spread?
Long-lived seeds are locally dispersed by gravity, but can also be moved in soil.
What damage does it do?
Rapidly occupying vacant spaces on road edges, or forest edge work sites, preventing regeneration or native species.
Which habitats is it likely to invade?
Roadsides, waste places and disturbed areas, scrub, margins of exotic plantation forests and coastal ecosystems. Prefers sandy soils, wetland margins and damp areas.
What can I do to get rid of it?
1. Pull or dig small plants (all year round). Ensure minimum soil disturbance. If not in seed, plant material can then be mulched.
2. Cut trunk and paint stump (all year round): cut trunk near to the ground, and swab freshly cut stump with triclopyr 600g/L (undiluted) or metsulfuron-methyl 600g/kg (5g/L).
3. Overall spray (spring-summer): triclopyr 600g/L (60ml/10L + penetrant)
What can I do to stop it coming back?
Plant area with natives to shade out prickly Moses seeding. Regeneration can be sped up by slashing and selective spraying. Clear roads and quarries and maintain pest and livestock control, as it is not readily grazed.