Physcia subalbinea Nyl. = Physcia caesia var. caesiella (B. de Lesd.) Clauzade & Cl. Roux

    Differs from the Physcia caesia canonical type by its thallus, its lobes markedly discrete, plane or slightly convex, mostly not overlapping, notably towards the margin, upper surface covered with large dots or conspicuous whitish macula and labriform soralia, white-greyish to bluish towards the center, becoming globose terminal soralia when old; lower surface dark. Uncommon variety, found on very dirty and exposed  siliceous rocks.*