When I posted the moss photo a while back, I didn’t really have a clear idea about what the difference was between moss and lichen. I did some Googling and got confused even more. Then, one Sunday, because Sam had to be in school for a few hours for a rehearsal, I was taking photos and asked one of the Science teachers, Sir Henry, what the difference was between moss and lichen. Fortunately, there was a lot of moss and lichen in school and he showed me. He even pointed out the different kinds of lichen.
So, the grayish spots on the tree in the photo above are lichen; the green growth in the older photo is definitely moss. Neither are parasitic to trees.
