World Register of Marine Species (WoRMS)
Compositae Working Group (CWG) (2026). Global Compositae Database. Cirsium horridulum Michx.. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1103915 on 2026-08-02
Michaux, A. (1803). Flora boreali-americana. 2.