Lichen  (Caloplaca aractina)

Caloplaca aractina is a 'crustose' lichen; one with a crusty-like appearance. The body of the lichen (its thallus) is an oily dark brown to grey colour, which means it can be overlooked against the rock on which it grows. The fruiting bodies are slightly more obvious when they appear, being orangey-brown in colour, sometimes bright red though very small (less than 1mm).