Extension > Garden > Diagnose a problem > Is this plant a weed? > Broadleaf Weeds > Basal > Plumeless Thistle
Plumeless Thistle
Carduus acanthoides L.
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Found in:
- Prairie and landscape 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:
- Minnesota Primary Noxious Weed that spreads rapidly and aggressively by seed
