A 2002 study of the molecular phylogeny of the agarics[3] indicated that the genus Psilocybe as then defined was polyphyletic, falling into two distinct clades that are not directly related to each other.

The phylogenetic study by Matheny et al., placed the non-bluing Psilocybe and its close relatives in a basal position within the Strophariaceae, a sister taxon to a clade containing the other genera within that family.

The bluing Psilocybe, however, form a clade that is sister to Galerina in the newly revised family, Hymenogastraceae that used to be restricted to secotioid, false-truffles.

[5] The suggestion was accepted by unanimous vote of the Nomenclature Committee for Fungi of the International Botanical Congress in 2010, meaning that P. semilanceata (a member of the bluing clade) now serves as the type species of the genus.

Microscopically, they are characterized by pileipellis with hyphae that run parallel to the pileus surface, forming a cutis, by their lack of chrysocystidia, and by spores that are smooth, ellipsoid to rhomboid to subhexagonal in shape, with a distinct apical germ pore.

Many of the species found in temperate regions, such as Psilocybe cyanescens, seem to have an affinity for landscaped areas mulched with woodchips and are actually rather rare in natural settings removed from human habitation.

The latter differs mainly by the location of one of the hydroxyls, and the addition of two methyl groups that make the molecule lipophilic (fat soluble), ergo capable of crossing the lipid membrane sheaths of the central nervous system.

Initially, hallucinogens were thought to blockade these serotonin neurotransmitters, but persistent research led to this agonist effect conclusion.

Shamans, or curanderas would avidly ingest the "sacred mushrooms" for the extrasensory perceptual effects it gave them in order to better assess problems faced in their society.

Hallucinogenic species of Psilocybe have a long history of use among the native peoples of Mesoamerica for religious communion, divination, and healing, from pre-Columbian times up to the present day.

Hallucinogenic Psilocybe were known to the aboriginal Mexicans as teonanácatl (literally "divine mushroom")[30] and were reportedly served at the coronation of Moctezuma II in 1502.

After the Spanish conquest of the Americas, the use of hallucinogenic plants and mushrooms, like other pre-Christian traditions, was forcibly suppressed and driven underground.

[38] Garcia was an avid observer of the fungi in his environment while identifying specific characteristics about the fruit body of the Psilocybe his ancestors utilized, as well as knowing where they could be found.

By the early 1970s, a number of psychoactive Psilocybe species were described from temperate North America, Europe, and Asia and were widely collected.

The purified chemicals psilocybin and psilocin are listed as Schedule II drugs under the United Nations 1971 Convention on Psychotropic Substances.

[45] If not authorized by law, possession of spores or cultivation of fruiting bodies of the Psilocybe is punishable to not more than one year in county jail or state prison.

[45] Psilocybin mushrooms as well as other "soft drugs" which are stronger than cannabis but not synthetic, are legally available through smart shops in the Netherlands.

Only the truffle form of magic mushrooms (such as P. tampanensis) are currently legal, but these still contain the active ingredients and produce similar effect as the caps and stalks.