The Rock

I guess moss does like damp shade . . .

if there is direct light then moss prefers to be on the shadier side. if shady all round then it will grow anywhere. Needs to be damp as they don't have any roots in fact no vascular tissue at all. Every 'leaf' is in fact only single cell thick.

That's fascinating Eileen. So is that lighter green lichen? Is moss & lichen related?

It looks like lichen. they are not related to mosses at all. Lichen is an odd thing. It is a mutualistic relationship between a fungus and an algae or cyanobacteria. Depending on which fungus and which algae or cyanobacteria are present will determine which lichen you get. the same fungus with different algae again look totally different.

how odd thanks for the info