Euro+Med Plantbase integrates and critically evaluates information from Flora Europaea, Med-Checklist, the Flora of Macaronesia,
and from regional and national floras and checklists from the area as well as additional taxonomic and floristic literature. This is
complemented by the European taxa of several families taken from the World Checklist of Selected Plant Families and of the
Leguminosae from the International Legume Database and Information Service ILDIS (see credits for details). By 1st of February 2018 it provides access to the total European flora of vascular plants in
222 plant families.
"Carduus gayanus" sec. Smythies, B. E. (1984) - Flora of Spain and the Balearic Islands. Checklist of vascular plants, 1 - Englera; Veröffentlichungen aus dem botanischen Garten und botanischen Museum, Berlin-Dahlem Berlin 3: 1-212.
"Carduus gayanus" sec. Devesa, J. A. & Talavera, S. - Revision del género Carduus (Compositae) en la Península Ibérica e Islas Baleares. Sevilla 1981.