Xanthoria calcicola Oxner var. calcicola (Taxon Atlantique). Forme verruqueuse.

    Thallus thick, made of lobes rather long and narrow, apices of lobes sometimes widened, indented, golden-yellow, orange, bright orange with in some places minute warts corresponding to atrophied urn-shaped apothecia or aborted warted excrescences of thallus. Located in general at the top of isolated bird-perching rocks or boulders in the sunny aerohaline zone. This form is easily (and often has been! ) confused with the  Xanthoria calcicola type that has more or less true coralloid isidia, or with some forms of Xanthoria aureola, and above all with Xanthoria aureola forme de la zone aerohaline that grows in the same habitat. (this below are under study and will be sequenced to know their relationship with this last taxon). Moreover, this form can be difficult to separate from certain warty forms of Xanthoria parietina (see here the examples Cf. of Saint-Nic).