Crust Fungus

A white crust fungus, probably Byssomerulius corium, on a fallen birch branch (Betula sp).

The following image shows the meruloid underside of a fragment growing on a thin twig:

This fragment yielded the following spores (shown at x600):

With an image width of 86um, these spores are about 5.5 x 2.5um, which is consistent with the values in the region of 5-7 x 2.5-3.5um given in the descriptions listed at Mycobank.

First photo and specimen taken in the Wilderness, Whiteknights Park, Reading, UK, on 2012-12-25.