Gymnopilus terrestris

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.

Fruiting body containing fibers (usually in the stalk)

Gills not free
Spore print tan, orange, deep ochre, yellowish olive, olive brown, rusty or cinnamon brown or deep brown
Ring usually either absent or not membranous

Growing on wood

Cap usually more than 2" across, and sometimes up to 8; usually tan, yellow, or pumpkin-colored

Spore print orange, rusty orange, or bright rusty brown
Entire fruiting body some shade of pumpkin-color or golden yellow; some species with tints or patches of other colors, or with tiny differently colored scales.
A drop of ammonia or KOH will stain the cap blackish
Flesh typically yellow
Taste typically bitter
Often growing cestipose

Gymnopilus terrestris     Hesler