Onopordum acanthium

Scotch Cottonthistle

Erect. Stem usually single, widely branched above, lightly covered with scratchy hairs and spines. Leaves widely attached with wide spiny wings running down stems, toothed or shallowly lobed with 8–10 pairs of widely triangular lobes, very spiny. Purplish rose or white flower heads are single or clustered, cobwebby, spined. Found in disturbed soils at low to mid elevations. Noxious weed introduced from Eurasia. Similar bull thistle, Cirsium vulgare, has narrow leaves shallow to deeply lobed and toothed with harsh spines on leaf surface. Onopordum (or onopordon) refers to the ability of plants from this genus to cause flatulence in donkeys.

  • Rarity: Common
  • Flowering Time: Mid Summer
  • Life Cycle: Biennial
  • Height: 2--4 feet
  • Habitat: Disturbed, Meadow
  • Found In:
  • Native: No

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