Compositae Working Group (CWG) (2021). Global Compositae Database. Pentacalia verticillata (Klatt) Cuatrec.. Accessed at: https://compositae.org/aphia.php?p=taxdetails&id=1101250 on 2024-09-23
original description(ofSenecio verticillatus Klatt)(1881 [1882]). Abhandlungen der Naturforschenden Gesellschaft zu Halle 15(2): page(s): 331. [details]