Carduus crispus, the Welted thistle or Curly plumeless thistle, is a biennial herb in the Asteraceae—daisy family. It is native to Europe and Asia.
The plant is found from Southwestern Europe, through Scandinavia and Siberia, to Eastern Asia. It is also found in Jammu and Kashmir of northern India.
The species and genus is a favorite foodplant of caterpillars of the Painted Lady butterfly (Vanessa cardui), which derives its specific epithet, cardui, from their preference for Carduus thistles. It is also used by bees for honey production.
Extracts from this plant have been found to have anti-cancer properties, the main one of which being Crispine B.
It's also said to hold alterative and anodyne properties in its roots.
Carduus crispus is an introduced species in North America, and a noxious weed in several U.S. states, including West Virginia.