Ivy gourd

Thought to be native to India, Asia and central Africa, ivy gourd is a smothering vine. It is recorded as an invasive weed on the Pacific islands of Saipan, Fiji, Guam, Tongatapu, the Solomons and Hawaii.

In Australia, ivy gourd is found in the Kimberley region of Western Australia, and in Arnhem Land, Darwin and the Gulf region in the Northern Territory. North Queensland currently has small, scattered populations. Ivy gourd can smother vegetation and other objects, forming a dense canopy. It has the potential to spread if not controlled.

Ivy gourd is not a prohibited or restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Coccinia grandis

Description

  • Perennial vine up to 13m tall, which forms dense, hanging mats that cover shrubs and small trees.
  • Stems are green, slender when young, becoming succulent and thick with age.
  • Stems develop roots where nodes contact soil.
  • Leaves are alternate, heart- to pentagon-shaped, up to 10cm wide and long.
  • Flowers are white, star-shaped, have 5 narrow sepals 6-8mm long that join at base.
  • Male flowers have 3 convoluted stamens.
  • Female flowers have 3 hairy stigmas.
  • Fruit is red, ovoid to elliptical, 25-60mm long, 15-35mm in diameter, hairless, on stalks 10-40mm long.
  • Seeds are tan, 6-7mm long.

Habitat

  • Native range habitat is deciduous bush, savanna, dry evergreen forest and thickets.
  • Prefers open, disturbed sites and riparian habitats in dry tropics of north Queensland.

Distribution

  • Found near Townsville, Cairns and other parts of coastal northern Queensland.

Life cycle

  • Seeds do not show dormancy, and usually germinate in 2-4 weeks.
  • Flowers August-September.

Impacts

Environmental

  • Smothers vegetation and other objects, forming dense canopy.

Economic

  • Hosts melon fly (crop pest) and, possibly, ring spot virus.

How it is spread

  • Spread from seeds and broken pieces of roots and stems.
  • Seeds can be dispersed by birds and feral pigs.

Control

Physical control

  • Very difficult to control, as all roots and stem fragments must be removed or plants will regrow from tuberous root system.

Herbicide control

  • No herbicide currently registered for control of ivy gourd in Queensland. Off-label use permit (Permit No. PER11463) allows use of various herbicides to control environmental weeds in non-agricultural areas, bushland, forests, wetlands, and coastal and adjacent areas.
  • In Hawaii, foliar application has proved successful only on small, young plants.
  • Cut-stump application of herbicides will be more effective.

Biological control

  • No known biological control agents.
  • However, 2 weevils (Acythopeus burkhartorum and A. cocciniae) are being trialled in Hawaii.

Legal requirements

  • Ivy gourd 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