| Author | (Muhlenberg ex Willdenow) Sprengel | |
| Distribution | Mountains, and scattered in the northern and western Piedmont. Possibly absent in the southwestern mountains.
Eastern Canada south to central AL and central TX. | |
| Abundance | Fairly common in the Mountains, except rare to absent in the southwestern counties. Rare to locally uncommon in the northern and western Piedmont. | |
| Habitat | Wooded borders, thickets, pastures, and other early succession and edge habitats. | |
| Phenology | Flowers and fruits August-November. | |
| Identification | This is a tall thistle quite similar to Tall Thistle (C. altissimum) in general appearance; it often reaches 4-6 feet tall. The purple-pink heads are numerous and rather large, about 25-35 mm high, as with that species. It can be separated from that species by its deeply dissected leaves, cut almost to the midrib. Swamp Thistle (C. muticum) is also a tall species with dissected leaves, but the spines on the involucre bracts are extremely short or lacking, but these bracts are quite sticky, whereas the bracts are spiny (over 1 mm long) and not sticky in C. discolor. | |
| Taxonomic Comments | None
| |
| Other Common Name(s) | Pasture Thistle (the common name usually given to C. pumilum) | |
| State Rank | S3? [S3] | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | UPL link |
| USACE-emp | UPL link |
