- Native to Europe.
- Monocarpic perennial.
- Produces an abundance of seeds, up to 2000 seeds (30-80% are viable).
- Can grow up to 6 feet tall.
- Large taproot, up to 2 feet in length.
- Large purple flower heads, blooms from June-September.
- Tolerates a variety of soils, from dry to wet.
- Limited to the Rossland, Warfield and Trail area.
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 flowering stalk down before full bud stage.
- Cutting flowering stems may need to be repeated for several years.
- Chemical control may work on larger infestations.
More information available:
- Central Kootenay Invasive Species Society: CKISS Plant Profile
- Wisconsin Department of Natural Resources: www.dnr.wi.gov
- Missouri Department of Conservation: www.mdc.mo.gov
- University of Wisconsin: http://www.youtube.com
- Natural Resources Conservation Service: www.efotg.sc.egov.usda.gov