Compositae Working Group (CWG) (2021). Global Compositae Database. Helianthus rydbergii Britton. Accessed at: https://www.compositae.org/aphia.php?p=taxdetails&id=1171370 on 2024-11-01
Contributed data: Notes Data only shown for fields conflicting with the consensus taxon record as "Rydbergi" [Tropicos] [details] LSID urn:lsid:compositae.org:names:47CD5AC5-F270-4843-A0F8-20242B1585AB [details] Taxonomy Oct 1901 [details] Type material 1767, P.A.Rydberg, null NY [details]