Canada thistle (Cirsium arvense L.)
Canada thistle has waxy, kelly green, serrated leaves and stems that branch out into many flower heads. Flowers are purple in the early season and become white when ready to go to seed.
Canada thistle is a perennial that spreads from both seeds and root systems, which makes control particularly difficult. Infestations usually begin in disturbed soil, and a combination of control methods are needed to eliminate it.