Compositae Working Group (CWG) (2021). Global Compositae Database. Carduus helleri Small. Accessed at: https://www.compositae.org/aphia.php?p=taxdetails&id=1147406 on 2024-10-17
original description(1903). Fl. S.E. U.S. [Small].[details]
Unreviewed
Contributed data: Published Data only shown for fields conflicting with the consensus taxon record Fl. S.E. U.S. [Govaerts World Compositae Checklist A-G] Flora of the Southeastern United States [Tropicos] [details] LSID urn:lsid:compositae.org:names:DB4DC89C-A275-4CC9-88C1-F60CC9FA1C2C [details] Taxonomy 22 Jul 1903 [details]