Compositae Working Group (CWG) (2021). Global Compositae Database. Helianthus rigidus var. subrhomboideus (Rydb.) Cronquist. Accessed at: https://www.compositae.org/aphia.php?p=taxdetails&id=1231877 on 2025-04-06
Contributed data: Full Name Data only shown for fields conflicting with the consensus taxon record Helianthus rigidus (Cass.) Desf. var. subrhomboideus (Rydb.) Cronquist [Preliminary Checklist of North American Compositae] Helianthus rigidus Desf. var. subrhomboideus (Rydb.) Cronquist [IPNI] [details] Contributed data: Published Data only shown for fields conflicting with the consensus taxon record Flora of the Pacific Northwest [Tropicos] [details] LSID urn:lsid:compositae.org:names:CFC5175C-A4EA-4542-BE06-7FD52F0A91D2 [details]