The mycelium is not always present - it tends to develop under humid conditions such as behind damp skirings etc, as a blackish to olive-brown sheet.
If no mycelium is present then it can be difficult to identify from other brown rots.
In most cases the rot is 'internal' and leaves a very thin skin of sound wood at the surface. This can be used to suggest the damge might be 'cellar' fungus.
Fruting bodies are brown, flat, thin plate-like structures with small protuberances. Coniophora puteana is bounded by a white margin.Mycelium and strands can develop away from the wood over the surface of very damp masonry and other surfaces under very humid conditions.
Frequently, fine brown/black strands emenate from rotting wood and these are quire delicate and do not become brittle on drying. In the very early stages, the strands may be white but soon darken.
