PicTure taken at Fornells, Costa Brava, close the sea, 15 m. altitude, flat position.
Crustose lichen, thallus light grey with a greenish tinge, continous, granular, cracked, with a very thin black prothallus. Apothecia up to 1,3 mm diam, black disdc, flat, wide margin, becoming crenulate, of the same colour than the thallus.
It resambles a lot R. confragosa (In this virtual guide with picture coming from Fontromeu) but R. beccariana only grows in Mediterranean climate place and specially close the sea, R. confragosa grows upland.
See pictures in:
F. Donson, Lichens, pag. 393
V. Wirth et alter, Lóquenes, musgos y hepáticas, pag. 217