Cirsium arvense

Canada Thistle

Stems erect, in dense colonies. Leaves sessile, green on both sides, lance-shaped, lobed, with short spines. Flower heads small, red to pink or lavender. Cup 3/4 in. high. Dioecious. Grows in fields, open areas, disturbed soils, at low to mid elevations. A noxious weed sometimes found in great abundance.

  • Rarity: Common
  • Flowering Time: All Summer
  • Life Cycle: Perennial
  • Height: 20--40 inches
  • Habitat: Meadow, West-Side Forest, East-Side Forest, Disturbed, Coastal
  • Found In: Olympic Np, Mt. Rainier Np, N Cascades Np
  • Native: No

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