Gymnopilus validipes is a widely distributed mushroom of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. Gymnopilus validipes contains the hallucinogens psilocybin

Psilocybin

Psilocybin is a naturally occurring psychedelic prodrug, with mind-altering effects similar to those of LSD and mescaline, after it is converted to psilocin. The effects can include altered thinking processes, perceptual distortions, an altered sense of time, and spiritual experiences, as well as...

 and psilocin

Psilocin

Psilocin , an aromatic compound, sometimes also spelled psilocine, psilocyn, or psilotsin, is a psychedelic mushroom alkaloid. It is found in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin...

. The mild taste of this mushroom stands in contrast to closely related bitter species. Validipes means "having a robust stalk."
Gymnopilus validipes contains about 0.12% psilocybin

Psilocybin

Psilocybin is a naturally occurring psychedelic prodrug, with mind-altering effects similar to those of LSD and mescaline, after it is converted to psilocin. The effects can include altered thinking processes, perceptual distortions, an altered sense of time, and spiritual experiences, as well as...

.

Description

• Pileus
  Pileus (mycology)
  The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
  
  : (4)7.5 — 15(30) cm, Convex to broadly convex, margin deeply incurved at first, becoming revolute with age, dry, fibrillose or with small ochraceous brown scales, pale-yellow or ochraceous buff, flesh soft, whitish, yellowish near the gills.
• Gills: Adnate to uncinate, close, thin, yellowish white becoming cinnamon.
• Spore Print: Orangish brown.
• Stipe
  Stipe (mycology)
  thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
  
  : (7.5)10 — 13(25) cm. long, (1.5)2.5 — 5 cm. thick, equal or swelling in the middle, fleshy-fibrous, solid, elastic, fibrillose, concolorous, white within, the cortina leaves only a faint ring on the robust stalk.
• Taste: Mild.
• Odor: Pleasant.
• Microscopic features: Spores (7.5)8 — 10 X 5 — 6, ellipsoid.

Habitat and formation

Gymnopilus validipes is found growing gregarious to cespitose on tree stumps, hardwood logs and debris, widespread in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, common from the Great Lakes

Great Lakes

The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

and eastward.