Psilocybin
Psilocybin and psilocin contain mainly psilocybin mushrooms of the genera Psilocybe and Panaeolus.(There are several other types of hallucinogenic mushrooms containing these alkaloids, belonging to the genera Inocybe, Conocybe, Gymnopilius, Psatyrella, but their role is relatively small.) Psilocybin mushrooms grow practically all over the world: in Europe, in both Americas, Australia, Oceania, Africa etc. Their species for different places differ, but it is practically difficult to find a place where any species of fungi such as Psilocybe Cubensis or Panaeolus did not grow at some time, under any conditions. Most likely, not only knowledge about their varieties is growing, but also their distribution area. Hallucinogenic mushrooms are 100% saprophytes, that is, they live by decomposing organic matter (unlike other fungi - parasitic (living at the expense of the host) or mycorrhizal (forming a symbiotic relationship with tree roots).
Psilocybin mushrooms populate well "disturbed" biocenoses, that is, roughly speaking, places where there is no longer nature, but not yet asphalt, and there are a lot of them on Earth. For some reason, hallucinogenic mushrooms like to grow close to humans; they are almost never found in the wilderness.
Their main habitat is wet meadows and meadows; many psilocybin mushrooms prefer cow or horse dung in these meadows. There are many types of hallucinogenic mushrooms, and they are, in fact, quite diverse both in appearance and in their preferences. Many of the hallucinogenic mushrooms turn blue when they break, although this sign cannot be considered either necessary or sufficient for identification, much less for consumption. The chemical nature of this blue discoloration is unknown, although it is most likely related to the reaction of psilocin in air.
Psilocybin mushrooms differ in psilocin and psilocybin content;a large, complete table of this information is published by Paul Stamets in Psilocybine Mushrooms of the World. Such information in relation to each specific type of mushroom is practically important (how much there is; how to store), but little has been accumulated. There are very "strong" mushrooms, for example, Psilocybe cyanescens, growing in the northwestern United States, in the humid forests of Washington state; there are much less active; for many species such data are still not established. Almost every year, new species of Psilocybe and others are described, mainly from little explored regions of the Earth; but the famous "power" "Astoria", for example, has also been described quite recently, although it is growing in the USA. Gaston Guzman, one of the main specialists in their taxonomy, says that even in his Mexico, where he studies their half life, there are still many undescribed species of mushrooms.