Canada Thistle (Cirsium Arvense)

Canada thistle is an herbaceous perennial that has upright grooved and hairy stems that branch out near the top of the plant. It grows 2-6.5 feet tall

Leaves: Leaves are green with spiny toothed edges. When young they are smooth but with age become hairy or downy.

Flowers: There are numerous small purple to pink flowers with spineless tips. Blooms between June and September

Fruits & Seeds: Seeds are small, light brown and have tan hair loosely attached to the tip to enable wind dispersal. Seeds most often are spread by mowing after the flowing has begun.

Roots: Has horizontal roots that grow up to 10-12' per year and also had taproots that can grow more then 6' deep.

Ecological threats

  • Canada thistle invades forest openings, oak savannas, prairies, dunes, agricultural fields, pastures and roadsides.
  • Once established in an area Canada thistle will spread and take over the area very quickly.

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