Blastenia crenularia var. contigua = Caloplaca crenularia var. contigua (A. Massal.) Cl. Roux

    This form differs from the type by its grey thallus, thick, cracked, forming areola with a rough or squamulose appearence, and by its numerous apothecia, sometimes poorly developped or aborted, grouped in small clusters. This thermophilic form, not often seen, can be found on sunny rocks, very exposed and under sea sprays, where it may alternately moisturize and dry.

N.B. If the thallus is thick and dark; blackish to dark gray with large protruding pycnidia see Kuettlingeria (Caloplaca) fuscoatroides which occurs in the xeric supralittoral zone.