Magic truffles, also called "Philosopher's stone" and Nuggets of Wisdom, are actually no truffles, but sclerotia of Psilocybe mushrooms. Sclerotia are mycelium thickenings growing underground and are part of the fungus, just as the fruiting bodies that appear above the ground.
The interesting part: The sclerotium of a fungus contains the same ingredients as those detected in the fruiting body. Thus the so called magic truffles are fully valid carrier of the entheogenic molecules psilocybin, psilocin and baeocystin/norbaeocystin.
But not all species of the genus Psilocybe form sclerotia. This characteristic was first discovered in Psilocybe Mexicana. Psilocybe Tampanensis and Psilocybe Atlantis have a habit of forming sclerotia as well, but magic truffles are not generally known by their generic name, but rather as Sclerotia Tampanensis, Sclerotia Mexicana etc.
Moreover, some Panaeolus species (mottlegill) that also contain psilocybin, for example, Panaeolus cyanescens, also form sclerotia, but not in such an exuberant form, as it is the case with the Psilocybe species. Through the dedicated efforts of some fans over the years a small number of new breeds has been established, with most them originating in the Netherlands, such as Psilocybe Mokum (Mokum = Syn. Amsterdam), Psilocybe Utopia and Psilocybe Hollandia.