Opegrapha corticola Coppins & P. James
Lichenised.
Substrate: bark
Altitudinal distribution: submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus)
Note: a western European, mild-temperate species growing on the trunks of ancient trees, especially Quercus ilex; easy to overlook, being always sterile, but certainly extremely rare; with a few records from the Western Alps.
