Trichaptum abietinum, the purplepore bracket, on a spruce log.

At Bod Petryal, Glocaenog Forest, Denbighshire. On a fallen conifer trunk, presumed to be Spruce, were a series of small thin caps, running along the trunk in loose tiers which turned out to be, almost certainly, Trichaptum abietinum. On closer examination the purple colours on the underside and edges of the caps were quite obvious, so on Spruce this is a very probable outcome. There are two other species of Trichaptum on conifers, but both are so rare in the UK that I am therefore discounting them, although T. fuscoviolaceum would be the next most likely. 

This is a very common saprophyte on fallen timber and stumps. The purple tends to fade as the annual brackets age, leaving the light brown as the dominant colour of the caps. Some caps appear more whitish above, most likely due to age and condition. At the same time the pores tend to become jagged and toothlike, rather breaking up, and this is the more normal condition. In the images below the lower tiers of brackets show most purple tinging, which seems to be associated with the pale edging visible.

The caps are slightly fuzzy above, and algae do tend to accumulate there near the base where the fuzziness tends to be most obvious, as seen below.

The colour of the cut branch stub on the right is unexplained.