Common Name:
Canada Thistle
Scientific Name:
Cirsium arvense (L.) Scop.
Family:
Asteraceae


Photo courtesy of
Corlene Rose, CES

Description: Canada thistle is a perennial that reproduces by seed and deep, creeping roots. Stems are from 1 to 4 feet tall and branching. The leaves have spine-tipped lobes. Flower heads are purple, and individual flowers are all rayed. Male and female flowers occur on separate plants. Canada thistle is native to Europe.

Control: Perennial plants require depletion of nutrient reserves in the root system, prevention of seed production and prevention of dispersal. This plant is not easily pulled due to its tough, spiny leaves. The roots should not be broken up. Individual root pieces may produce new plants.