Lichen (Placynthium nigrum)
I know lichen are an aquired taste and people in general prefer the more exotic flowers such as orchids or the more dramatic animals such as birds and I do try an enthse people with these lower organisms which are all too often over looked but I can find little say in support of Placynthium nigrum!
It is a dull, black crust that grows on hard calcarious substrates and so is very common on walls and tombstones. Apart from being black and crusty there is little else one can add really! Looking at it, it is hard to believe it is actually a living thing, it could just be some sort of powder someone dropped accidentally. However, it is a living organism and if you look at under maginifaction it is more interesting. Why not take a look?
Find out more about the nature of Dorset at my website www.natureofdorset.co.uk