Mimosa pigra

Alert

Have you seen Mimosa pigra?

Be on the lookout for Mimosa pigra and report it to Biosecurity Queensland. Early detection and reporting are the key elements in controlling Mimosa pigra.

Call us on 13 25 23.

Native to tropical America, the Mimosa pigra shrub spreads aggressively in moist environments and establishes dense thickets that smother other vegetation. Mimosa pigra is a serious weed in several tropical countries and is well-established across 800,000ha of floodplains in the Northern Territory. It has the potential to colonise other wetlands in tropical Australia.

In Queensland, Mimosa pigra has been found at Peter Faust Dam near Proserpine.

Mimosa pigra is a restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Mimosa pigra

Other names

Giant sensitive tree, thorny sensitive plant, giant mimosa, catclaw mimosa, bashful plant

Description

  • 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.

Habitat

  • 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.

Distribution in Queensland

  • Found in 1 recorded infestation near Proserpine.

Life cycle

  • 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.

Affected animals

Livestock; Humans

Impacts

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.

How it is spread

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

Control

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.

Legal requirements

  • Mimosa pigra is a restricted invasive plant under the Biosecurity Act 2014.
  • All sightings must be reported to Biosecurity Queensland within 24 hours of the sighting.
  • By law, everyone has a general biosecurity obligation (GBO) to take all reasonable and practical steps to minimise the risk of spread of the plant until they receive advice from an authorised officer.

More information