4 Strains

Inocybe is a large genus of agaric mushroom of the Inocybaceae family.
The epithet Inocybe translates from Latin to “fibrous hat”.
Members of this genus are known to live in the roots of vascular host plants. This mycorrhizal relationship with the root system of various plants makes Inocybe amongst the most highly adaptative type of mushrooms. After all, it is said that mycelium is the largest living organism on earth, like a fungal world wide web, also part of what some call the “wood wide web”.
With over 1400 species including a mixture of edible, psychoactive and poisonous mushrooms, this genus has the reputation of being a “mycological minefield”.
Even Dr. Daniel Stuntz, who spent several decades studying the genus and estimated 400-600 species, was only able to recognize approximately 150. This gives a good idea of the difficulty to accurately identify this genus even for the most experienced mycologists, over the span of a lifetime!
Though some species may be slightly lilac, Inocybes have the typical “little brown mushroom” morphology, with usually small conical caps flattening with age, and often a distinctive musty “spermatic” odor.
Out of the thousands of mushrooms included in this genus, only five are known to contain the psychoactive tryptamine alkaloids psilocin and psilocybin. These strains are Inocybe aeruginascens, I. corydalina var corydalina, I. corydalina var erinaceomorpha, I. coelestium, and I. haemacta.
Because most Inocybe contain muscarine, a toxic alkaloid that can cause convulsion and death, it is said few people have bio assayed psilocybin-active Inocybes; data more likely came from chemical analyses rather than from personal experience (which is a good thing!). Though, exceptionally, in the case of Inocybe aeruginascens, it was an unfortunate intoxication back in 1983, while mistaking the psychoactive mushroom to the common fairy ring mushroom Marismius oreades, that revealed for the first time the presence of psilocybin in this specie!
The unusual feature of this small mycorrhizal tabacco-coloured fungus is that it contains almost equal amounts of three serotonin-like hallucinogenic compounds: psilocybin, baeocystin, and aeruginascin (the latter compound is believed to modify the pharmacological action of psilocybin.)
Nonetheless, because with this genus, it is most likely that you will find one that is toxic, it is with no doubt advised to “psychonauts” to refrain from ingesting any Inocybes found growing naturally in the wild.
Because Inocybes are so ambiguous to identify, most have not been tested for their toxicity, edibility nor psilocybin activity. In his book Psilocybin Mushrooms of the World, Paul Stamet even refrains from associating any pictures to the genus. He also suggest that there is no reason to believe that muscarine and psilocybin should be mutually exclusive and wonders if someday, we will discover a specie that produces both.