Parkinsonia

• This small, hairless tree grows up to 10m tall.
• Branches are slender and zigzag-shaped with sharp spines.
• Leaves have short, spine-tipped stalks.
• Leaf branches are 20–40cm long.
• Flowers are yellow, fragrant and 5-petalled. Each is on a long, slender, drooping stalk.
• Seed pods are pencil-like, 5–10cm long and constricted between seeds.
• Seeds are oval, are about 15mm long and have a thick, extremely hard coat.

3D model

• View the 3D model to help you identify this plant. You can magnify the image and manipulate the view to inspect the plant from every angle.

• Occurs most abundantly on flood plains but is adaptable to a wide range of soil types.
• Found along watercourses in subhumid and semi-arid areas of Queensland.

• Visit the Weeds Australia website and click on the distribution tab to view the distribution map.

• The plant flowers in early summer of its second or third year, then exploits variable seasonal conditions.
• Pods mature in late summer and are readily dispersed by floodwaters.
• Seeds remain viable until favourable conditions occur.

Environmental

• Forms dense, often impenetrable thorny thickets along watercourses and bore drains.
• Invades flooded country via floating seeds.
• Provides a haven for feral pigs, which prey on livestock, damage crops, and degrade the environment.

Economic

• Reduces pasture production.
• Restricts stock access to drinking water and makes mustering almost impossible.

• Spread primarily by floodwaters.
• Possibly also spread by mud sticking to vehicles and animals.

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

Physical control

Fire

• To obtain the best results, use slow-moving grassfires that maintain heat around the base of plants for as long as possible. Seedlings are most susceptible to fire, but you can achieve moderate to high kills of larger plants with this treatment.
• You may need to spell before burning to build a fuel load. Control grazing pressure afterwards to re-establish a competitive pasture.

Mechanical control

• You can achieve effective initial clearing by stickraking, blade ploughing or ripping.
• Restrict clearing to reasonably level areas away from watercourses.
• Because clearing will hasten seed germination, apply follow-up control (either mechanical or chemical).

Herbicide control

Aerial application

• For aerial application, use purpose-built applicators attached to aircraft. This technique is useful for dense, strategic infestations, but it may be expensive on a broad scale and needs to be done in accord with vegetation management legislation.

Foliar spray

• This is an effective control method for seedlings up to 1.5m tall. Spray leaf and stems to the point of run-off and use a wetting agent.

Basal bark spray

• For stems up to 15cm in diameter, carefully spray around the base of the plant to 30cm above ground level. To control larger trees, spray to a greater height, up to 100cm above ground level.
• Spray plants when they are actively growing (preferably flowering) and when there is good soil moisture.
• Infested areas are often subject to flooding, so ensure mud and flood debris do not prevent spray penetration to the bark. You may need to clear trunks before spraying.

Cut stump treatment

• This can be performed year-round. Cut stems off horizontally as close to the ground as possible. Within 15 seconds, swab or spray the cut surface and associated stem with herbicide mixture.

Soil application

• Use 1 dose of herbicide per metre of tree height. Place doses close to the tree trunk, either on clear, bare ground using a spot gun or underground using a ground injector. Rain or sufficient soil moisture is needed for the herbicide to be taken up by plant.
• Do not use herbicides near watercourses or desirable trees (for trees, allow a clearance distance of at least twice the height of the trees).

Read the parkinsonia fact sheet to find out more about herbicide control and application rates.

Biological control

• Four species of insects have been introduced.
• Both Penthobruchus germaini and Mimosetes ulkei are seed beetles that attack only parkinsonia. Their larvae destroy mature parkinsonia seeds. Penthobruchus germaini may be giving some control.
• The parkinsonia leaf bug Rhinacloa callicrates is a small green bug imported from the United States.
• The leaf-feeding looper Eueupithecia cisplatensis has been introduced from Argentina.
• Naturally occurring fungal pathogens have been identified as causing dieback in many infestations of parkinsonia across northern Australia. Studies are continuing regarding the use of these pathogens as biological control tools.

• Parkinsonia is a category 3 restricted invasive plant under the Biosecurity Act 2014. You must not:
  • give it away
  • sell it
  • release it into the environment.

  If you do any of these, penalties may apply.

• You must take all reasonable and practical measures that are under your control to minimise the biosecurity risks associated with dealing with parkinsonia. This is part of your general biosecurity obligation.
• 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 parkinsonia. Some of these actions may be required under local laws. Contact your local government for more information.