Reindeer Lichen (Cladonia portentosa)
Whilst there are various similar species of 'reindeer lichen' there is only one found here. The others are confined to the Arctic tundra and is a favourite food of ... reindeer, of course!
Not much look at at first glance but get down close, add a bit of magnification and you have this wondrous mass of intricate 'branchlets' that spread out in all directions to make delicate, fluffy, tufted mats.
In some books this can be listed as Cladonia impexa as some lichens are being reclassified after DNA analysis reveals more about them and their relationship to other lichens.