- Solitary yellow flower at the end of a stem about 1 metre 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 damages nerve centers in the brains of horses, which control eating and drinking habits.
- Outcompetes native plants and grasses resulting in decreased biodiversity
Introduction and spread
- Often spread on equipment and vehicles, especially with the transportation of livestock.
- Seeds have been found in wildflower seed mixes and grass seed.
Status in the CKISS region
- Yellow starthistle is classified as Prevent on the CKISS Annual Priority List.
- This species is also classified as Provincial EDRR by the provincial government, and is managed by the Province.
- This species is not currently known to be present in BC.
- Please report any sightings immediately to the Province.
- To learn more about how CKISS classifies and manages invasive species, see our Invasive Species Priority Lists page.
Integrated pest management options
- It is important to check what seeds are in wildflower 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 and brush off your boots when leaving an infested area.
- Small infestations can be controlled by hand pulling before plants flower.
- Mowing when the plant is beginning to flower is another option.
- Infestations must be treated as early as possible to be the most effective.