Parasitic lichen?

Parasitic lichen?

Observation - Parasitic lichen?. Description: Grey areolate crustose lichen with dark prothallus (possibly Aspicilia caesiocinerea) growing on siliceous rock seems to be being taken over by a larger structured light yellow crustose lichen with bigger areoles and with black apothecia. Parasitic liche

Grey areolate crustose lichen with dark prothallus (possibly Aspicilia caesiocinerea) growing on siliceous rock seems to be being taken over by a larger structured light yellow crustose lichen with bigger areoles and with black apothecia. Parasitic lichen possibly Rhizocarpon viridiatrum.