Senegal tea

Native to South America, Senegal tea is an aquatic perennial introduced to Australia as an aquarium plant. In the wild, it invades and degrades natural wetlands. The first infestations of Senegal tea were found in New South Wales and Tasmania.

You must manage the impacts of Senegal tea on your land.

You must not give away, sell or release Senegal tea into the environment.

Scientific name

Gymnocoronis spilanthoides

Description

  • Aquatic perennial that grows over water surface, producing runners and floating stems up to 2.5m long.
  • On land, grows as rounded bush.
  • Leaves are shiny, dark green, 5–20cm long, in opposite pairs.
  • Stems are hollow between nodes, allowing plant to float.
  • Young stems are light green with dark green blotches.
  • Young stems are round, becoming 6-sided as plant grows.
  • Flowers are white, pompom-like, 15–20mm in diameter.
  • Seeds are yellow-brown, ribbed.

Habitat

  • Favours shallow and slow-moving water.
  • Can grow over water surface or in wet, marshy soils.

Distribution

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

Life cycle

  • Seeds germinate in spring and, if conditions are right, in summer.
  • Flowering starts in late spring to early summer.
  • Becomes dormant when temperatures drop.

Affected animals

  • Wetland birds

Impacts

Environmental

  • Forms floating mats, blocking irrigation ditches, shallow dams and waterways.
  • Invades and degrades natural wetlands.

How it is spread

  • Spread through cultivation and sale as an aquarium or ornamental water plant, and through dumping of aquarium contents into waterways.
  • Spread by broken stem, leaf fragments and seed.
  • Seeds spread by water, and in soil on vehicle tyres and animals' feet.

Control

If you find an infestation of Senegal tea, please contact Biosecurity Queensland. Do not attempt to control this weed, as it needs to be positively identified so all occurrences can be recorded before control.

Mechanical control

  • Place all removed plant material in sealed plastic bag, leave in sunlight to decompose, then dispose of at council-approved landfill tip. Alternatively, leave material in sun to dry, then burn.
  • Do not leave broken plant pieces in growth area.

Herbicide control

  • Biosecurity Queensland is seeking a minor use permit from the Australian Pesticides and Veterinary Medicines Authority for herbicides suitable for use.

See the Senegal tea fact sheet (PDF, 190KB) for herbicide control and application rates.

Biological control

  • No known biological control agents.

Legal requirements

  • Senegal tea is a category 3 restricted invasive plant under the Biosecurity Act 2014.
  • You must not give away, sell or release Senegal tea into the environment. Penalties may apply.
  • You must take all reasonable and practical measures to minimise the biosecurity risks associated with dealing with Senegal tea under your control. This is called a general biosecurity obligation (GBO).
  • At a local level, each local government must have a biosecurity plan that covers invasive plants in its area. This plan may include actions to be taken on Senegal tea. Some of these actions may be required under local laws. Contact your local government for more information.

Further information