Compositae Working Group (CWG) (2025). Global Compositae Database. Pentacalia verticillata (Klatt) Cuatrec.. Accessed at: https://www.compositae.org/gcd/aphia.php?p=taxdetails&id=1101250 on 2025-03-11
original description(ofSenecio verticillatus Klatt)(1881 [1882]). Abhandlungen der Naturforschenden Gesellschaft zu Halle 15(2): page(s): 331. [details]