Psilocybe tampanensis forms psychoactive truffle-like sclerotia that are known and sold under the nickname "philosopher's stones".

The species was described scientifically by Steven H. Pollock and Mexican mycologist and Psilocybe authority Gastón Guzmán in a 1978 Mycotaxon publication.

[1] According to Paul Stamets, Pollock skipped a "boring taxonomic conference" near Tampa, Florida to go mushroom hunting, and found a single specimen growing in a sand dune, which he did not recognize.

[1] Guzmán classified P. tampanensis in his section Mexicanae, a grouping of related Psilocybe species characterized primarily by having spores with lengths greater than 8 micrometers.

Spores appear brownish-yellow when mounted in a solution of potassium hydroxide, and have a thick, smooth wall, a distinct germ pore, and a short appendage.

In 1996, Guzmán reported finding it in a meadow with sandy soil in a deciduous forest in Pearl River County, Mississippi, a habitat similar to that of the type location.

[10] Psilocybe tampanensis contains the psychedelic compounds psilocin and psilocybin, and is consumed for recreational and entheogenic purposes.

[11] According to mycologist Michael Beug, dried fruit bodies can contain up to 1% psilocybin and psilocin;[7] in terms of psychoactive potency, Stamets considers the mushroom "moderately to highly active".

[15] Methods were originally developed by Pollock,[16] and later extended by Stamets in the 1980s to cultivate the sclerotia on a substrate of rye grass (Lolium), and on straw.

In the United States, Federal law was passed in 1971 that put the psychoactive components into the most restricted schedule I category.

[19] In parallel legal developments in Asia, P. tampanensis was one of 13 psychoactive mushrooms specifically prohibited by law in Japan in 2002.