Identify Invasive Species

Canada Thistle

Plant

Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and northern Asia, and widely introduced elsewhere. The standard English name in its native area is creeping thistle. Wikipedia

Scientific name: Cirsium arvense

Family: Asteraceae

Kingdom: Plantae

Rank: Species

Higher classification: Cirsium

Did you know: The Canada thistle is the only thistle with female and male flowers appearing on separate plants.

South Dakota State Noxious Weed

Type	Information
Toxicity	Non-toxic.
Control	Cutting or mowing, biological, re-vegetation (competing crops) and herbicide. Contact your County Weed District or local Applicator for more information. See 525N for herbicide recommendations.
Habitat	Wetter habitat or disturbed ground, including ditch banks, overgrazed pastures, tilled fields or abandoned sites.
Root	Extensive vertical and creeping horizontal roots.
Leaf Shape	Lance-shaped and shallow-lobed.
Lifespan	Perennial; two years or longer.
South Dakota State Weed	Abundant in South Dakota and widespread in many counties.
Similar Looking Plants	Wavy leaf and bull thistles.
Important Information	Hard to manage due to extensive nutrient stores and root systems; combinw integrated weed management (IWM) for effective control. The root system accounts for much of the re-establishment of the plant.

Identify Invasive Species

Canada Thistle

South Dakota State Noxious Weed

Common Tansy

Lawrence County Locally Declared

Common Mullein

Lawrence County Locally Declared

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Type	Information
Toxicity	Can cause abortions in humans if ingested; will cause liver damage in some livestock, but it is largely palatable.
Control	Mechanical and herbicide. Contact your County Weed District or local Applicator for more information. See 525N for herbicide recommendations.
Habitat	Full sun and moist habitats along stream banks, irrigation ditches, trails and roadsides, lawns and gardens, waste areas, vacant lots and pastures.
Root	Extensive, spreading root system.
Leaf Shape	Alternate on stem and fern-like.
Lifespan	Perennial; two years or longer.
Locally Declared	Abundant in Lawrence County and other Black Hills counties.
Similar Looking Plants	Tansy ragwort and camphor tansy.
Important Information	Often still planted and cultivated as an ornamental. Also can be used as a natural insect repellent.