Carduus discolor (Muhlenberg ex Willdenow) Nuttall

Carduus discolor (Muhlenberg ex Willdenow) Nuttall is a synonym sensu FNA Ed. Comm., 2006a of:

Cirsium discolor (Muhlenberg ex Willdenow) Sprengel, an accepted species name sensu FNA Ed. Comm., 2006a.