Weeds of National Significance

To help focus national efforts to address weed problems in Australia, a list of Weeds of National Significance was compiled. Plant species were selected on the basis of their invasiveness and impact characteristics, their potential and current area of spread and their primary industry, environmental and socioeconomic impacts.

In Western Australia many Weeds of National Significance are also declared pests under the Biosecurity and Agriculture Management Act 2007.

To protect Western Australia’s agriculture the Department of Primary Industries and Regional Development:

  • regulates weeds under the Biosecurity and Agriculture Management Act 2007
  • provides a weed identification service
  • provides information on weed control, crop weeds, regulated/declared plants and herbicides.

For advice on Weeds of National Significance in Western Australia search our website, the Western Australian Organism List or contact our Pest and Disease Information Service (PaDIS).


  • Silverleaf nightshade (Solanum elaeagnifolium) is a declared pest in Western Australia (WA).

  • Willows (Salix species except S. babylonica, S. x calodendron, and S.

  • This article provides information on aquatic weeds that are declared plants in Western Australia. Prevention is the cheaper option!

  • Madeira vine (Anredera cordifolia) has been designated as a Weed of National Significance (WoNS).

  • Parkinsonia (Parkinsonia aculeata

  • Control methods for Parkinsonia (Parkinsonia aculeata) a declared pest in Western Australia.

  • Parthenium weedragweed, Santa Maria feverfew, bitter weed, carrot grass, congress grass, false ragweed, ragweed parthenium, whitetop 

  • Serrated tussock (Nassella trichotoma) is a declared pest in Western Australia (WA).

  • Control methods for salvinia (Salvinia molesta) a declared pest in Western Australia. Report the presence of this organism before undertaking a control measure.

  • Mesquite (all Prosopis species and hybrids) are declared pests in Western Australia (WA).