A biennial with a short fleshy taproot, the plant grows to a height of 2-4 feet. It has large urn-shaped bracts with a pinkish to purple flower. A native of Eurasia, it is now widespread in Colorado and throughout the United States. It is distinguished from other thistles in that the leaves are hairy and prickly on top and cottony underneath.
It is commonly found on moist sites such as drainage or irrigation ditches or stream beds. Preventing seed production should be the goal when trying to control this plant.