Peat Moss (Sphagnum capillifolium)
Not easy to photograph in a way that does it justice, Sphagnum is made up of masses of much smaller plants all growing together in a tight colony. Normally it is found in large compact cushions just above the water table in bogs, on heathland and in damp acid woodland.
Sphagnum acts like a sponge, it holds lots of water as a protection against drying out if the water levels drop in drier weather. This 'capillary' action gives it its name, 'capillifolium'; foliage that soaks up water.
My little field guide lists eleven species of Sphagnum mosses, all incredibly similar, and eight are found in Britain. I am pretty sure however, this is 'capillifolium' unless anyone can tell me otherwise!