Xanthoria calcicola Oxner var. calcicola (Taxon Atlantique). Forme sans isidies ni verrues.

    Differs from the type by the lack of warts as well as isidia (even though the beginning of minute folioles towards thallus center may be observed), apothecia usually  present, disc orange, exciple thin, paler often excluded at maturity. At the basis or on walls of rocks of the foreshore, from the xeric to the aerohaline zone, mixed with other forms of Xanthoria aureola and Xanthoria parietina that are very similar. N.B. This "intermediate" taxon will be sequenced to clarify its relationship with Xanthoria aureola and Xanthoria parietina.