Psilocybe cubensis
Psilocybe cubensis is a species of psychedelic mushroom whose principle active compounds are psilocybin and psilocin. Psilocybe cubensis belongs to the Strophariaceae family of fungi and was previously known as Stropharia cubensis. The mushroom's cap is reddish-cinnamon brown to golden brown in color with white to yellowish stipe and will turn bluish/greenish when bruised.

# Overview
Psilocybe cubensis is a coprophilic fungus (one that prefers to grow on dung or manured soils) that often colonizes the dung of large herbivores, most notably cows and other grazing mammals.  It prefers humid grasslands and has been found in tropical and subtropical environments. In the US, it is sometimes found growing wild in the South, generally below the 35th parallel in Alabama, Florida, Louisiana, Mississippi, Texas.  It is found in Mexico, Belize, Costa Rica, Guatemala, Cuba, Dominican Republic, Guadalupe, Martinique, Puerto Rico, Trinidad, Argentina, Bolivia, Brazil, Colombia, French Guiana, Peru, Cambodia, India, Malaysia, Philippines, Thailand, Vietnam, Australia, Tasmania, New Zealand and Fiji.
This species was first described as Stropharia cubensis by F.S. Earle in Cuba in 1904 (hence the specific name). The name  Psilocybe  is derived from the Greek roots psilos () and kube () and translates as "bald head". It was later identified independently as Naematoloma caerulescens in Tonkin in 1907 by N. Patouillard and as Stropharia cyanescens by W.A. Murrill in 1941 in Florida. These synonyms were later assigned to the species Psilocybe cubensis.

# Entheogenic use
Its major psychoactive compounds are:
- Psilocybin (4-Phosphoryloxy-N,N-dimethyltryptamine)
- Psilocin (4-hydroxy-N,N-dimethyltryptamine)
- Baeocystin (4-Phosphoryloxy-N-methyltryptamine)
- Norbaeocystin (4-Phosphoryloxytryptamine)
Individual brain chemistry and psychological predisposition play a significant role in determining appropriate doses. For a modest psychedelic effect, a minimum of one gram of dried Psilocybe cubensis mushrooms is ingested orally. 0.25-1 gram is usually sufficient to produce a mild effect, 1-2.5 grams usually provides a moderate effect. 2.5 grams and higher usually produces strong effects. For most people, 3.5 dried grams (1/8 oz) would be considered a high dose and may produce an intense experience. For many individuals doses above 3 grams may be overwhelming. For a few rare people, doses as small as 0.25 grams can produce full-blown effects normally associated with very high doses. For most people, however, that dose level would result in virtually no effects. Due to factors such as age and storage method, the psilocybin content of a given sample of mushrooms will vary.  Therefore, some users prefer to use a formula or dosage calculator  to tailor the dosage to the level they wish to experience.
Effects usually start after approximately 20-60 minutes (depending on method of ingestion and stomach contents) and may last from four to five hours, depending on dosage. Hallucinatory effects often occur, including walls that seem to breathe, a vivid enhancement of colors and the animation of organic shapes. At higher doses, experiences tend to be less social and more entheogenic, often intense and spiritual in nature.
It's nearly impossible to overdose on psilocybin mushrooms since one would have to consume nearly their entire body weight in fresh mushrooms or 1680g of dried mushrooms. Nevertheless, the effects of very high doses can be overwhelming. Depending on the particular strain, growth method, and age at harvest, Psilocybe cubensis mushrooms can come in rather different sizes. It is recommended that one weigh the actual mushrooms, as opposed to simply counting them. People taking MAOIs need to be careful, as psilocybin and psilocin are metabolized by the enzyme monoamine oxidase. An MAOI reduces the body's ability to handle the mushrooms (roughly doubling their potency), and can lead to an unpleasant, prolonged, or dangerously strong experience.

# Legality
Although it is illegal in many countries to possess psilocybin-containing mushrooms or mycelium (which can contain psychoactive substances at certain stages), it is legal in several places to own and sell spores.  In the United States only the psychoactive compounds (see above) are scheduled under federal law.  The spores do not contain either (but possession is prohibited by state law in Idaho, Georgia and California).

# Cultivation
Personal-scale cultivation of Psilocybe cubensis mushrooms ranges from the relatively simple and small-scale PF Tek and other "cake" methods, that produce a limited amount of mushrooms, to advanced techniques utilizing methods of professional mushroom cultivators, such as Paul Stamets. These advanced methods require a greater investment of time, money, and knowledge, but reward the diligent cultivator with far larger and much more consistent harvests.  A number of books and online guides have been written that discuss the various techniques. The Shroomery and Mycotopia are two of the largest and most notable internet communities dedicated to sharing this type of information. Extreme caution is suggested if one is seeking to find psilocybin mushrooms in the wild; there are many mushrooms that look similar to Psilocybe cubensis that are actually poisonous. Cultivation of wild mushrooms is greatly discouraged because many look-alike species are deadly; unless one is an expert of mycology and ethnobotany, he should refrain from this activity.

# Notes
-  Stamets, Paul (1996). Psilocybin Mushrooms of the World. Ten Speed Press. pp. pg. 108. ISBN 0-89815-839-7..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
-  Jump up to: 2.0 2.1 A Worldwide Geographic Distribution of the Neurotropic Fungi
-  Erowid (2006). "Erowid Psilocybin Mushroom Vault: Dosage" (shtml). Erowid. Retrieved 2006-11-26.
-  Shroomery (2006). "How many dried mushrooms would I have to eat to die from an overdose of psilocybin?". Mind Media. Retrieved 2006-11-26.
-  Erowid (2006). "Legality of Psilocybin Mushroom Spores" (shtml). Erowid. Retrieved 2006-11-26.

# Further reading
- Nicholas, L.G. (2006). Psilocybin Mushroom Handbook: Easy Indoor and Outdoor Cultivation. Quick American Archives. ISBN 0-932551-71-8. Unknown parameter |coauthors= ignored (help)
- Oss, O.T. (1976). Psilocybin: Magic Mushroom Grower's Guide. Quick American Publishing Company. ISBN 0-932551-06-8. Unknown parameter |coauthors= ignored (help)
- Stamets, Paul (1983). Mushroom Cultivator, The. Olympia: Agarikon Press. ISBN 0-9610798-0-0. Unknown parameter |coauthors= ignored (help)
- Stamets, Paul (1996). Psilocybin Mushrooms of the World. Berkeley: Ten Speed Press. ISBN 0-9610798-0-0.