Also known as
What does it look like?
Spiny scrambling shrub (<15m tall). Young shoots finely ribbed and rounded, and stems are woody, with tapering, hooked spines where stems join with leaves, occasionally in pairs. Leaves are divided twice, first evenly into 5-10 leaflet pairs (8-20mm long) with no terminal leaflet, then into 6-12 pairs of tiny oval leaflets. Pale yellow, pea-like flowers (15 mm long) are grouped along the end of the stems (Jun-Nov), and are followed broad, oblong pods (7-10 x 2-3 cm) containing smooth, mottled brown seeds (8-10 mm long).
Why is it weedy?
Very quick growing and maturing, and produces many well-dispersed seeds. Thicket-forming, long-lived. Tolerates wind, salt, hot, drought, poor soils, moderate shade.
How does it spread?
Seeds are spread by soil and water movement and wind.
What damage does it do?
Forms impenetrable thickets, preventing native species from establishing, and killing all plants growing above and below it.
Which habitats is it likely to invade?
Disturbed forest and shrubland, fernland, open sites in coastal forest; potentially in Northland.
What can I do to get rid of it?
1. Dig out small patches (all year round): dispose of at refuse transfer station, burn or bury.
2. Cut trunk and paint stump (all year round): cut trunk near to the ground, and swab freshly cut stump with metsulfuron-methyl 600g/kg (2g/L) or a product containing 100g picloram+300g triclopyr/L (100ml/L).
3. Overall spray (spring-summer): metsulfuron-methyl 600 g/kg (5g/10L + penetrant) or a product containing 100g picloram+300g triclopyr/L (25ml/10L).
What can I do to stop it coming back?
Major potential pest, eliminate in all warmer areas. Follow up for 5+ years, then replant with dense shading species.