Cucumber tree

Native to Mexico and Central America, cucumber tree is a short-trunked tree with cucumber-like fruit.

It was introduced to Australia as an ornamental and for its edible fruit. Cucumber tree has invaded rainforest in some far north Queensland catchments, out-competing and replacing native vegetation.

Cucumber tree is not a prohibited or restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Parmentiera aculeata

Description

  • Small to large tree with short, thick trunk.
  • Bark is pale.
  • Branches have short, stout spines at nodes.
  • Leaves are compound, opposite, trifoliate, on long, narrow-winged leaf stalks with 3 elliptical leaflets each 4-8cm long.
  • Flowers are trumpet-shaped, green, with brown-purple lines, 5-6.5cm long.
  • Fruit are cucumber-like, ridged, yellow-green with red stains, 11-17cm long, 2-3cm wide, often curved.

Habitat

  • Prefers riparian areas and invaded rainforest.

Distribution

  • Found in Cairns-Gordonvale area and, occasionally, on Atherton Tableland.

Life cycle

  • Usually buds in August and flowers from September.
  • Produces many windblown seeds.
  • Can germinate during wet summer periods and develop within 12 weeks to flower the following spring.

Impacts

Environmental

  • Invades rainforest in some far north Queensland catchments.
  • Out-competes native rainforest trees.
  • Replaces native vegetation.

How it is spread

  • Seeds spread by water and birds.

Control

Physical control

  • Manually remove seedlings.
  • If larger plants are cut down or ringbarked, treat stump with suitable herbicide or tree will reshoot.

Mechanical control

  • Cultivation, grubbing, hoeing and burning, along with planting of competitive pastures and fertilisation, will control weed in accessible areas.

Herbicide control

  • No herbicide is currently registered for control of cucumber tree in Queensland. Off-label use permit (Permit No. PER11463) allows use of various herbicides for control of environmental weeds in non-agricultural areas, bushland, forests, wetlands, and coastal and adjacent areas.

See the Cucumber tree fact sheet (PDF, 745KB) for herbicide control and application rates.

Biological control

  • No known biological control agents.

Legal requirements

  • Cucumber tree is not a prohibited or restricted invasive plant under the Biosecurity Act 2014. However, by law, everyone has a general biosecurity obligation (GBO) to take reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control.
  • Local governments must have a biosecurity plan that covers invasive plants and animals in their area. This plan may include actions to be taken on certain species. Some of these actions may be required under local laws. Contact your local government for more information.

Further information