P. cyanescens

Psilocybe cyanescens (sometimes referred to as the potent Psilocybe or as wavy caps) is a species of potent psychedelic mushroom. The main compounds responsible for its psychedelic effects are psilocybin and psilocin. It belongs to the family Strophariaceae. A formal description of the species was published by Elsie Wakefield in 1946 in the Transactions of the British Mycological Society, based on a specimen she had recently collected at Kew Gardens. She had begun collecting the species as early as 1910.

In 1962, a six-year-old girl in Oregon experienced a high fever and seizure after eating mushrooms which were later identified as Psilocybe cyanescens; she died three days after being hospitalized. Similar cases in children (not resulting in death) have been reported in San Francisco. Despite these incidents, the mushroom is not generally regarded as being physically dangerous to adults. Since all the psychoactive compounds in P. cyanescens are water soluble, the fruiting bodies can be rendered non-psychoactive through parboiling, allowing their culinary use. However, since most people find them overly bitter and they are too small to have great nutritive value, this is not frequently done.

Psilocybe cyanescens can sometimes fruit in colossal quantity; more than 100,000 mushrooms were found growing in a single patch at a racetrack in England.

Psilocybin mushrooms, also known as psychedelic mushrooms, are fungi that contain psychoactive indole alkaloids. There are multiple colloquial terms for psilocybin mushrooms, the most common being shrooms and magic mushrooms. Biological genera containing psilocybin mushrooms include Agrocybe, Conocybe, Copelandia, Galerina, Gerronema, Gymnopilus, Hypholoma, Inocybe, Mycena, Panaeolus, Pluteus, and Psilocybe. There are approximately 190 species of psilocybin mushrooms and most of them fall in the genus Psilocybe.

Psilocybin mushrooms have likely been used since prehistoric times and may have been depicted in rock art. Many cultures have used these mushrooms in religious rites. In modern Western society they are used recreationally for their psychedelic effects. Recent studies done at Imperial College London and Johns Hopkins School of Medicine conclude that when used properly, psilocybin acts as an anti-depressant as suggested by fMRI brain scans.

Psilocin (also known as 4-HO-DMT, psilocine, psilocyn, or psilotsin), is a substituted tryptamine alkaloid and a serotonergic psychedelic drug. It is present in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin. Psilocin is a Schedule I drug under the Convention on Psychotropic Substances. The mind-altering effects of psilocin are highly variable and subjective and resemble those of LSD and mescaline.

Psilocybin (pron.: /ˌsɪləˈsaɪbɪn/ SIL-ə-SY-bin) is a naturally occurring psychedelic compound produced by more than 200 species of mushrooms, collectively known as psilocybin mushrooms. The most potent are members of the genus Psilocybe, such as P. azurescens, P. semilanceata, and P. cyanescens, but psilocybin has also been isolated from about a dozen other genera. As a prodrug, psilocybin is quickly converted by the body to psilocin, which has mind-altering effects similar to those of LSD and mescaline. The effects generally include euphoria, visual and mental hallucinations, changes in perception, a distorted sense of time, and spiritual experiences, and can include possible adverse reactions such as nausea and panic attacks.

Psilocybe is a genus of small mushrooms growing worldwide. This genus is best known for its species with psychedelic properties, widely known as "magic mushrooms". Psilocin and psilocybin are the psychedelic compounds responsible for the psychoactive effects of many species in the genus.

A psychoactive drug, psychopharmaceutical, or psychotropic is a chemical substance that crosses the blood–brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in alterations in perception, mood, consciousness, cognition, and behavior. These substances may be used recreationally, to purposefully alter one's consciousness, or as entheogens, for ritual, spiritual, and/or shamanic purposes, as a tool for studying or augmenting the mind. Many psychoactive drugs have therapeutic utility, e.g., as anesthetics, analgesics, or for the treatment of psychiatric disorders.

Psychoactive substances often bring about subjective changes in consciousness and mood that the user may find pleasant (e.g. euphoria) or advantageous (e.g. increased alertness) and are thus reinforcing. Thus, many psychoactive substances are abused, that is, used excessively, despite health risks or negative consequences. With sustained use of some substances, psychological and physical dependence ("addiction") may develop, making the cycle of abuse even more difficult to interrupt. Drug rehabilitation aims to break this cycle of dependency, through a combination of psychotherapy, support groups, maintenance and even other psychoactive substances. However, the reverse is also true in some cases, that certain experiences on drugs may be so unfriendly and uncomforting that the user may never want to try the substance again. This is especially true of the deliriants (e.g. Jimson weed) and powerful dissociatives (e.g. Salvia divinorum). Most purely psychedelic drugs are considered to be non-addictive (LSD, psilocybin, mescaline etc.); "psychedelic amphetamines" or empathogen-entactogens (such as MDA, MDMA etc.) may produce an additional stimulant and/or euphoriant effect, and thus have an addiction potential.