Lichen

Half day today so I went for a quick mooch to Wisborough Green churchyard, and got carried away photographing the amazing array of lichen growing there.
This lichen in particular (the dark green one) interested me as it was growing on a smooth granite gravestone, something I have never seen before. I have no idea what it is, (lichen identity is a nightmare) but if anyone else does, that would be wonderful. 
It was so cold at the cemetery (it's on a hill), I was really glad to get back to my warm car, and even more glad to be snuggled up on the sofa! 
Can't wait to feel the sun on my back again