Mimosa pigra

• Erect, branched shrub up to 6m tall.
• Taproots branch and extend 1–2m deep.
• Thorns are rose-like, 5–10mm long.
• Leaves are bright green, fern-like, 20–25cm long.
• Central leaf stalk is prickly.
• Flowers are round, fluffy, pink, 1–2cm wide.
• Each flower produces cluster of 10–20 thickly haired seed pods, 6–8cm long.
• Each pod contains 20–25 oblong-shaped seeds, 4–5mm long and 2mm wide.

• Favours wet–dry tropical climate, in areas with more than 750mm annual rainfall and higher temperatures.
• May also pose problems in wetlands and around dams and waterways in areas with less than 750mm annual rainfall.
• Survives on a range of soil types and is found in moist situations such as floodplains and riverbanks.

• Mimosa pigra has been found at Peter Faust Dam near Proserpine.
• Visit Weeds Australia and click on the distribution tab to access the distribution map.

• Germinates when floodwaters recede in the dry season, or in the wet season between November–March in the Northern Territory.
• Flowering can occur as little as 2 months after germination and podding as early as 5 months after germination.
• Main flowering occurs January–May and podding March–July. Further flowering can occur at other times if moisture is sufficient.
• Seeding occurs approximately 3–6 weeks after flower bud forms.

Environmental

• Grows aggressively.
• Forms dense, impenetrable thickets, 3–6m tall.
• Establishes along riverbanks, encroaches into billabongs and out onto drier floodplains.

Economic

• Smothers pastures, reducing available grazing area, and affects stock mustering.

Social

• Affects access to water for recreation.

• Spread by floods, tidal movement, machinery, vehicles and boats.
• Also spread by seeds sticking to clothes, hair and animals.

• Find out how farmers can prevent weed spread.
• Find out how gardeners and outdoor enthusiasts can prevent weed spread.

Herbicide control

• Permit no. PER12926 allows the use of metsulfuron for control of Mimosa pigra.

Biological control

• Thirteen biological control agents have been released in the Northern Territory.
• Three of these, the insects Neurostrota gunniella, Malacorhinus irregularis and Coelocephalapion pigrae, were released in Queensland in 2006 but failed to establish.

• Mimosa pigra is a category 2, 3, 4 and 5 restricted invasive plant under the Biosecurity Act 2014.
• It must not be kept, moved, given away, sold, or released into the environment. Penalties may apply.
• All sightings of Mimosa pigra must be reported to Biosecurity Queensland within 24 hours of the sighting.
• You must take all reasonable and practical measures to minimise the biosecurity risks associated with dealing with Mimosa pigra under your control. This is called a general biosecurity obligation (GBO).
• At a local level, each local government agency must have a biosecurity plan that covers invasive plants in its area. This plan may include actions to be taken on Mimosa pigra. Some of these actions may be required under local laws. Contact your local council for more information.