Cirsium discolor is a biennial or short-lived perennial member of the Asteraceae that is native to the eastern half of North America. It occurs in tallgrass prairies, moist meadows, glades, old fields, pastures, and openings in woods, reaching heights of up to 8 feet tall. While it can be found in quality habitats, C. discolor also can withstand quite a bit of degradation. Unlike C. arvense (Canada Thistle), which spreads by rhizomes, C. discolor has a taproot and does not form colonies. The genus name Cirsium comes in part from the Greek word cirsos, meaning "swollen vein," as thistle was once used to treat this ailment. The specific epithet discolor is a reference to the leaves being different colors (green on the top and densely white hairy on the underside).