Ganoderma tsugae

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

Polyporus radicatusStipitoporus     Tribe
Not fitting the other choices, fruiting body with well-developed stem

Ganoderma applanatumGanoderma     Genus
Either cap shiny reddish brown (as if varnished), or dull brown with a white pore surface that turns brown when scratched
Cap often with a white margin.
Pores minute (4-7 per mm), almost too small to see.
Spores reddish-brown.
Causes a white rot

Ganoderma lucidumGanoderma     Section
Entire cap surface (except for white margin) orange, orange-brown or reddish-brown, shiny as if varnished (reddish-brown spores may accumulate on top of the cap and partially hide this feature)
Pore surface may gradually discolor with age, but not quickly upon bruising

Ganoderma tsugae     Murrill

Here are the characters that distinguish this species from the others in its group. For its more general characters, see higher up on the page.
If there's just a few words or a microscopic feature here, a more thorough description can be found above.

Ganoderma lucidum