- Native to Europe and Asia.
- Biennial or perennial.
- In the Sunflower family.
- Tall, coarse, spiny thistle.
- Can grow to 2 or more meters tall.
- Branched stems with spin-margined wings.
- Large purple flower heads.
- Tolerates a variety of soils, prefers moist soils.
- Very limited distribution, single sites in Nelson, Castlegar, Rossland and Slocan valley.
Consequences of invasion
- May be competitive with native vegetation in rangelands.
- Forms dense stands that are impenetrable to livestock.
Integrated Pest Management Options
- Pull or dig small infestations when soil is moist.
- Cut a few inches below the soil surface.
- Mow or slash before seedset.
- Chemical control may work on larger infestations.
- Re-establish competitive perennial grasses and monitor yearly.