Carduus is a genus of flowering plants in the family Asteraceae, and the tribe Cardueae, one of two genera considered to be true thistles, the other being Cirsium. Plants of the genus are known commonly as plumeless thistles. They are native to temperate Eurasia and North Africa, and several are known elsewhere as introduced species. This genus is noted for its disproportionately high number of noxious weeds compared to other flowering plant genera.
Etymology
The genus name Carduus is from the Latin for "a kind of thistle" or "thistlelike plant". It is related to the word Cardonnacum ("a place of chardons or thistles"), which is the origin of Chardonnay, the name of the grape variety. It is also related to the word card, which as a noun means a device (often a stiff-bristled brush) for aligning and cleaning fibers, and as a verb means the action of processing fibers in that way.
