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Is this plant a weed?

Plumeless Thistle, Carduus acanthoides L.

Found in:

  • Prairie plantings

Characteristics:

  • Biennial plant that produces a basal rosette and large taproot the first year
  • Second year plant produces a flowering stem 3-6’ tall
  • Leaves are deeply lobed with white to yellowish spines (sharp, pointy tips on leaf edges)
  • Leaf hairs are scattered on the upper surface; denser hairs on lower surface especially along the mid-vein
  • Spiny winged peduncle (stem section just below flower head) separate it from Musk Thistle
  • Single or loosely clustered, reddish-purple flowers are globe-shaped, ½ -1” in diameter, with spiny bracts at the base of each flower
  • Flowers bloom late May through early July

Significance:

Plants that look similar:

More information and control options for Plumeless Thistle

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