Caloplaca maritima (de Lesd.) de Lesd.
Caloplaca interfulgens auct. p.p.
Thallus most often crustose, thin, seldom minutely lobate, extensively cracked-areolate, areoles thin, squamulose, snakeskin-like tinged with pearly gloss, overall colour yellow-ochrish to yellow in sheltered areas, golden-yellow in well lit situations, limited by an inconspicuous pale orange to whitish prothallus. Apothecia sessile, emerging from squamules, usually numerous and scattered, to 0.5-1 mm diam., disc plane at first later subconvex, with a clear thin thalline margin. yellow-ochre like beeswax. Ascospores ellipsoid, polarilocular, 1-septate, 11-15 x 5-8 µm. Photobiont: trebouxioid. K+ purple. Common, on vertical smooth, weakly acidic or neutral rocks,sometimes on stone walls near the seashore, most often above the Caloplaca marina zone which displays brighter orange colours. May equally be found as very large patches by juxtaposition of several colonies on rocks and walls near the sea when subjected to spray. Thalli colours are brighter in well lit zones and paler in shaded spots; specimen growing on walls or calcareous rocks are golden-yellow to orange and less fertile; on the same substratum provided that it remains humid, other yellow-lemon taxa with lobulate margin may be found. They still are under investigation and they seem to be a morphotype (or an ecotype) that we group together with Caloplaca maritima since all intermediates with type species exist. Not to be confused with Caloplaca marina that grows in a lower zone and with less numerous and smaller apothecia, more orange colours, its thallus often blackish and parasitised by cyanobacteria.