Amazing Lichen

I took a different route to work today as I had spotted this lichen covered tree a while ago and wanted to return for a closer look! although I couldn't get to close as the ground was very boggy, I managed to get it in reasonable focus with the zoom! It looked like a dying Willow, that was almost completely colonised by what I think is Usnea subfloridana, this species would be sensitive to sulphur dioxide pollution, good to know the air around here is clean!