Bracket Fungus

Brackets of Bjerkandera adusta growing on the end of a horse chestnut log (Aesculus hippocastanum).

The pore surface is grey and there are about 7 pores per mm.  This agrees with the 6-7 per m given here.  The similar Bjekandera fumosa has a white spore surface and only 2-5 pores per mm (see here)

The spores are about 4 x 2.5um (the field of view is about 86um wide).  This agrees with the 4.5–5.5 x 2.5–3um given here.

And the hyphae have clamp connections:

First photo and specimen taken in Whiteknights Park, Reading, UK, on 2013-12-07.