Green cestrum

Native to Chile and Peru, green cestrum is a perennial shrub with greenish-yellow flowers. It is an escaped garden plant that has become a weed of roadsides, creeks and neglected sites in central and South East Queensland. Green cestrum's seeds are poisonous to stock.

Green cestrum is not a prohibited or restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Cestrum parqui

Description

  • Perennial shrub up to 3m tall, with 1 or more stems emerging from each crown.
  • Leaves are alternate, up to 12cm long, 2.5cm wide.
  • Flowers are greenish-yellow, in clusters at ends of branches, unpleasant odour by day, fragrant at night.
  • Flower tubes are up to 2.5cm long with 5 small terminal lobes.
  • Berries are purplish-black, oval, about 1cm long, each contains 1 or 2 seeds.
  • Seeds have irregular shape and sharp angles 3-4mm long.

Habitat

  • Occurs commonly on vacant allotments, roadsides and creekbanks.
  • Prefers higher rainfall areas and tolerates frosts.

Distribution

  • Found in South East Queensland and some towns in central Queensland.

Life cycle

  • Plants flower after 2 years and are produced for several months through summer and autumn.
  • Plants are long-lived, producing new growth in spring.
  • Seeds germinate in autumn and remain dormant in soil for many years.

Affected animals

  • Livestock
  • domestic animals
  • humans

Impacts

Environmental

  • Out-competes vegetation on alluvial flats.

Economic

  • Poisonous to livestock, domestic animals, humans.

How it is spread

  • Spread mainly by bird-dispersed seeds.
  • Regenerates from root pieces to produce new infestations, particularly during crop cultivation or roadside grading.
  • Also spread by floodwaters.

Control

Mechanical control

  • Can be killed by completely digging out plants.
  • Take care to remove all yellow roots, otherwise plant will regrow.
  • Burning of roots is effective.

Herbicide control

  • Herbicides are effective.

See the Green cestrum fact sheet (PDF, 614KB) for herbicide control and application rates.

Biological control

  • No known biological control agents.

Legal requirements

  • Green cestrum 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