| Name | Cirsium perplexans (Rydberg) Petrak |
| Authorship | (Rydberg) Petrak |
| Rank | Species |
| Placed in | Cirsium Miller |
| Citation | 1917 Beih. Bot. Centralbl., Abt. 2. 35(2[2/3]): 441–442 |
| Holdings | 1 Specimen held in the Harvard University Herbaria identified as Cirsium perplexans (Rydberg) Petrak |
| Identification made in | [no date] (1) |