Bjerkandera     Genus

Cortinarius husseyiKey to Gilled Mushrooms     Key
This is a key to gilled mushrooms, that is, mushrooms having a definite cap with a fertile surface consisting of gills. The fruiting body usually also has a stem, although that may be lateral or absent (usually, then, the mushroom is growing from wood). You can use this key to identify mushrooms that you find.

Fomes fomentariusPolyporaceae     Family
Fertile surface usually a layer of vertical tubes, of which the mouths are visible as pores on the underside of the cap or shelf.
Fruiting bodies usually tougher or harder than the "normal" gilled mushrooms, being leathery, corky, or woody. But they can be quite tender while actively growing
Once grown, they do not decay easily, remaining on the substrate for months or years
They often grow on wood, although a few are terrestrial (even those are usually growing on buried wood)
Fruiting body is usually a flat shelf, or hoof-shaped, protruding directly from the substrate, although sometimes it may have a short stalk.
Some forms never grow away from the substrate at all, so that all that is visible of the fruiting body are the pores.
Sometimes the pores are so minute that the fertile surface seems solid, until you look closely

Phellinus ignariusLignicopolypore     Subfamily
Growing on wood

Whiteoporus     Tribe
Piptoporus betulinus
Sessile cap entirely white to buff
Pores concolorous or yellow or pale grey, sometimes darkening in age to grey or even black
Sometimes with moss or algae growing on the cap (coloring it green)
Links from Look-alikes
Small Imbricate Polypore     SemiTribe
Trametes versicolor
Fruiting in dense clusters of thin-fleshed shelving fruiting bodies

Bjerkandera     Genus     Karsten

Bjerkandera adusta


Narrow down your identification:

Bjerkandera adustaBjerkandera adusta
Cap thin (1-6 mm), hardly more than a backing for the tubes, maximum 3" wide.
Pores minute (5-7 per mm) and white at first (darkening where bruised) but soon becoming grey, darkening continuously until almost black.
The tomentum is often almost as thick as the fleshy part of the cap.
Lacking a black line

Bjerkandera fumosaBjerkandera fumosa
Cap fleshy, wider and thicker than B. adusta: up to half an inch thick and 4" wide, with a black line separating the pores from the cap
Has an anise-like (or unpleasant) odor
Pores larger and lighter than B. adusta: buff to smoky gray, 2-5 per mm