Pertusaria rupicola

Pertusaria rupicola is a species of saxicolous (rock-dwelling) crustose lichen belonging to the family Pertusariaceae. It is characterized by its thick, brain-like folded thallus that appears grey-greenish or yellow-green in colour. This organism produces distinctive wart-like fruiting bodies with black to pale yellow-brown openings. Native to the Mediterranean region, it grows primarily on steep, north-facing siliceous rock surfaces in well-lit but indirect sunlight environments. The species has experienced population declines following wildfires due to its slow growth rate. P. rupicola also serves as a host for the lichenicolous fungus species Lichenostigma rupicolae....read more on Wikipedia.