Gymnopilus luteus, known as the yellow gymnopilus, is a widely distributed mushroom-forming fungus of the Eastern United States.

It contains the hallucinogens psilocybin and psilocin.

[1] It is considered inedible due to the bitter taste and presence of the hallucinogenic compounds psilocybin and psilocin.

[1] G. luteus is found growing solitary to gregariously or in small clusters on dead hardwood trees, preferring damp and well rotted material.

It fruits from June to November, and is widely distributed in the eastern United States and Canada.