Yellow starthistle (Centaurea solstitialis)

Yellow starthistle

Centaurea solstitialis


  • Solitary yellow flower at the end of a stem about 1m tall
  • Sharp spines extend out from below the flower head
  • Stem is erect and blue-green coloured with fuzzy hairs. Grows in bunches and appears bush-like

Consequences of invasion

  • Infests rangeland and is fatally toxic to horses. The toxin kills nerve centers in the brains of horses, which control eating and drinking habits
  • Out competes native plants and grasses resulting in decreased biodiversity

How is it introduced? How does it spread?

  • An unwelcome hitchhiker on equipment and vehicles especially with the transportation of livestock
  • Seeds have been found amongst wild flower seed mixes and grass seed

Integrated Pest Management Options

  • It is important to check what seeds are in wild flower seed mixes before they are planted to avoid unintentional planting
  • Become PlantWise and learn about Grow Me Instead
  • Livestock that has been in pasture with these plants must not be transported to areas not yet infested
  • Check all clothing when leaving an area infested with scotch broom
  • Small infestations can be controlled by hand pulling
  • Infestations must be treated as early as possible to be the most effective
  • Mow when the plant is tall

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