Nice bit o'lichen

Think this is Xanthoria parietina, common one in the UK, I remember it because of the jam tarts, but it may not be.

Tonight there was a lot of baking happening. Nick volunteered me and him to make the cakes this week, as once a week at the office someone makes/buys cakes and chooses a time for the whole office to drop everything and eat cake. Which is a bloody good idea really.