Stinkwort

Native to Africa, Asia and Europe, stinkwort is a poisonous annual herb with greyish green leaves and a strong, camphor-like smell.

Stinkwort is listed as a weed in many regions of the world, including South Africa, New Zealand, and California. It is found in much of southern Australia, including a small population in southern Queensland. Stinkwort can poison stock and invade cereal crops.

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

Scientific name

Dittrichia graveolens

Other names

  • Stinkweed, camphor inula

Description

  • Annual herb that forms rosette then grows erect to 20-50cm tall.
  • Plant is sticky to touch, covered in white hairs, strongly aromatic, with camphor-like smell.
  • Leaves are light grayish-green, sparse, alternate, 1-4cm long, 0.1-0.8cm wide.
  • Flower heads are small, 5-7mm in diameter, yellow rays with yellow to reddish disk, up to 500-700 flowers per mature plant.
  • Seeds are light brown, about 2mm long.

Habitat

  • Adapted to temperate, Mediterranean-type climate with annual rainfall of 300-800mm falling predominantly in winter.
  • Prefers disturbed, open (unshaded) habitats such as cultivated land, abandoned fields, roadsides and overgrazed pastures.

Distribution

  • Small population found in Stanthorpe district of South East Queensland.

Life cycle

  • Flowers in autumn.
  • Produces about 15,000 seeds.
  • Seeds last no more than 3 years and germinate in spring.

Impacts

Economic

  • Stock that ingest stinkwort can develop enteritis, leading to pulpy kidney disease and sudden death if untreated.
  • Invades cereal crops.

Social

  • Causes dermatitis in humans and animals.

How it is spread

  • Seeds are spread by wind, water, agricultural produce, machinery, vehicles and wool.
  • Wind can carry seeds more than 200m.

Control

Physical control

  • Hand-pulling or hoeing can be effective on isolated plants.

Herbicide control

  • 2,4-D ester has been used in some areas; however, herbicides generally cannot penetrate plant's oily leaves.

Biological control

  • No known biological control agents.

Legal requirements

  • Stinkwort 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