Parthenium Weed

(Parthenium hysterophorus)
Pathenium, photo: C. T. Bryson
Image above: parthenium weed plant, © C.T. Bryson

Status of parthenium weed in Tasmania

  • Parthenium weed is a declared weed in Tasmania under the Tasmanian Weed Management Act 1999. The importation, sale and distribution of parthenium weed are prohibited in Tasmania.
  • Parthenium weed is also a Weed of National Significance (WONS).
  • The legal responsibilities of landholders and other stakeholders in dealing with parthenium weed are laid out in the parthenium weed Statutory Weed Management Plan.

What does parthenium weed look like?

  • Parthenium weed is a branching, annual herb growing to 2 metres in height. The leaves are lobed and hairy. The flower heads are white and about 4 mm across, and are borne on branches arising from the leaf forks.
  • Parthenium weed spreads by seed. Seed is spread in water, on machinery and vehicles, by stock and feral animals, and in stock fodder, grain and feed.
  • See the WONS website for more information on identifying this weed.
Pathenium, photo: Hugh Wilson Pathenium, photo: Hugh Wilson
Images above: parthenium weed, plant & flowers, © Hugh Wilson.

Impacts of parthenium weed

  • Parthenium weed is a serious weed of pasture and cropping land. It is a threat to the biodiversity of native grasslands. It also causes severe allergic reactions in some people, including dermatitis, hay fever and asthma. It is toxic to cattle and can taint meat.

Where does parthenium weed occur?

  • Parthenium weed is a native of sub-tropical North and South America. In Australia, parthenium weed has naturalised in Queensland, New South Wales and the Northern Territory.
  • Parthenium weed does not occur in Tasmania.

What you need to do

  • If you locate parthenium weed anywhere in Tasmania, or if you find a plant that you think could be parthenium weed, immediately contact Biosecurity Tasmania on 03 6165 3777 to report this weed.
See also
Weeds of National Significance - Parthenium Weed

Other useful links
Pest Genie

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