It occurs solitarily or with several stems from one base and is highly branched above. Initial growth is in the form of a well developed basal rosette. Leaf surfaces are glabrous to densely pubescent, and margins are whitish to purplish. Cauline leaf blades are lanceolate to broadly elliptic, pinnatified into lanceolate to ovate spiny lobes, and glabrous to densely pubescent.
Peduncles are naked or with a few bractlets.
Two subspecies are of musk thistle are generally recognized. Nyman has not been reported in Minnesota may be found only in Wyoming, Montana, and South Dakota. Musk thistle is a highly competitive, noxious weed. A native of Eurasia, it was first reported in North America during the period of 1853 to 1866. Both early and later introductions may have been for ornamental uses.