Caloplaca filsonii

About

Caloplaca filsonii is a species of corticolous (bark-dwelling), crustose lichen in the family Teloschistaceae. It has a crust-like thallus that is uneven and warty around the edges and more distinctly wart-like in the centre, coloured in shades of grey and brownish-grey near its reproductive structures (apothecia), but lacking a developed prothallus.

Summary from Wikipedia