Caloplaca dalmatica (A. Massal.) H. Olivier

   Thallus crustose, medium thick, usually finely rimose-areolate, pale yellowish, yellow-ochre to yellow-orange, areoles designing a network of cracks, zigzag-shaped with more or less intersected  black lines and an usually delimited by a grey-black prothallus. Apothecia scarse to rather abundant, immersed at first, then sessile, 0,5-1 mm diam., disc flat, later sub-convex, yellow, orange to yellow-orange; thalline margin concolourous, conspicuous, often becoming excluded in old apothecia. Ascospores broadly ellipsoid, polarilocular, 1-septate, septum 3-5 µm wide, 1/4-1 /2 of the length of the ascospore, 9-13 x 5-9 µm. Photobiont : trebouxioid. Thallus and apothecia : K+ purple. On hard limestone rocks or of walls in sunny situations, sometimes on mortar of ancient walls of chapels. Not confuse with other yellow thallus species like Caloplaca ochracea which thallus is thinner and with different ascospores, and with Caloplaca flavovirescens which apothecia and ascospores  are larger and growing mainly on cement with a thallus devoid of zigzag-shaped deep black cracks. This species is subject to various interpretations according to authors; here we took on the interpretation of British authors.*