|Approximate Range of Psilocybe cubensis|
|gills on hymenium|
|cap is convex or flat|
|hymenium is adnate or adnexed|
|stipe has a ring|
|spore print is purple|
|ecology is saprotrophic|
Psilocybe cubensis is a species of psychedelic mushroom whose principal active compounds are psilocybin and psilocin. Commonly called shrooms, magic mushrooms, golden tops, cubes, or gold caps, it belongs to the Hymenogastraceae family of fungi and was previously known as Stropharia cubensis. It is the most well known psilocybin mushroom due to its wide distribution and ease of cultivation.
Taxonomy and naming
The species was first described in 1906 as Stropharia cubensis by Franklin Sumner Earle in Cuba. In 1907 it was identified as Naematoloma caerulescens in Tonkin by Narcisse Théophile Patouillard, while in 1941 it was called Stropharia cyanescens by William Alphonso Murrill in Florida. These synonyms were later assigned to the species Psilocybe cubensis.
The name Psilocybe is derived from the Greek roots psilos (ψιλος) and kubê (κυβη), and translates as "bare head". Cubensis means "coming from Cuba", and refers to the type locality published by Earle.
- Pileus: 2–8 cm (1–3 in), conic to convex, becoming broadly convex to plane in age, may retain a slight umbo, margin even, reddish-cinnamon brown when young becoming golden brown in age, viscid when moist, hygrophanous, glabrous, sometimes with white universal veil remnants decorating the cap, more or less smooth. Flesh whitish, bruising blue in age or where injured.
- Gills: adnate to adnexed to sometimes seceding attachment, close, narrow to slightly wider towards the center, at first pallid to gray, becoming dark purplish to blackish in age, somewhat mottled, edges remaining whitish.
- Spore print: dark purple brown
- Stipe: 4–15 cm (2–6 in) long, 0.5–3.8 cm (0.2–1.5 in) thick, white to yellowish in age, hollow or somewhat stuffed, the well developed veil leaves a persistent white membranous annulus whose surface usually becomes concolorous with the gills because of falling spores, bruising blue or bluish-green when injured.
- Taste: farinaceous
- Odor: farinaceous
- Microscopic features: spores 11.5–17 x 8–11 µm, subellipsoid, basidia 4-spored but sometimes 2- or 3-, pleurocystidia and cheilocystidia present.
Psychedelic and entheogenic use
- Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine)
- Psilocin (4-hydroxy-N,N-dimethyltryptamine)
- Baeocystin (4-phosphoryloxy-N-methyltryptamine)
- Norbaeocystin (4-phosphoryloxytryptamine)
The concentrations of psilocin and psilocybin, determined by high-performance liquid chromatography, were determined to be in the range of 0.14–0.42% and 0.37–1.30% (dry weight) in the whole mushroom, 0.17–0.78% and 0.44–1.35% in the cap and 0.09 and 0.30%/0.05–1.27% in the stem, respectively.
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; this is, however, typically considered a standard dose among recreational users. 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. Effects usually start after approximately 20–60 minutes (depending on method of ingestion and stomach contents) and may last from four to ten hours, depending on dosage. Visual distortions often occur, including walls that seem to breathe, a vivid enhancement of colors and the animation of organic shapes.
The effects of very high doses can be overwhelming depending on the particular phenotype of cubensis, growth method, and the individual. 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. A monoamine oxidase inhibitor reduces the body's ability to metabolize psilocin and psilocybin, greatly increasing the intensity of the experience. This can sometimes produce uncomfortable or undesirably intense experiences.
Psilocybin and psilocin are listed as Schedule I drugs under the United Nations 1971 Convention on Psychotropic Substances. However, mushrooms containing psilocybin and psilocin are not illegal in some parts of the world. For example, in Brazil they are legal, but extractions from the mushroom containing psilocybin and psilocin remain illegal. In the United States, Psilocybe cubensis is illegal in all states. However, as of May 8, 2019 Denver, Colorado has decriminalized it for those 21 and up. On June 4th, 2019, Oakland, California followed suit, decriminalizing psilocybin containing mushrooms as well as the Peyote cactus. On January 29, 2020, Santa Cruz, California decriminalized naturally-occurring psychedelics, including psilocybin mushrooms.
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. 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.
Terence and Dennis McKenna made Psilocybe cubensis particularly famous when they published Psilocybin: The Magic Mushroom Grower's Guide in the 1970s upon their return from the Amazon rainforest, having deduced new methods (based on pre-existing techniques originally described by J.P. San Antonio) for growing psilocybin mushrooms and assuring their audience that Psilocybe cubensis were amongst the easiest psilocybin-containing mushrooms to cultivate.
Potency of cultivated specimens can vary widely in accordance with each flush (harvest). In a classic paper published by Jeremy Bigwood and M.W. Beug, it was shown that with each flush, psilocybin levels varied somewhat unpredictably but were much the same on the first flush as they were on the last flush; however, psilocin was typically absent in the first two flushes but peaked by the fourth flush, making it the most potent. Two strains were also analyzed to determine potency in caps and stems: In one strain the caps contained generally twice as much psilocybin as the stems, but the small amount of psilocin present was entirely in the stems. In the other strain, a trace of psilocin was present in the cap but not in the stem; the cap and stem contained equal amounts of psilocybin. The study concluded that the levels of psilocybin and psilocin vary by over a factor of four in cultures of Psilocybe cubensis grown under controlled conditions. 
Relationship with cattle
With cow dung being the preferred habitat of Psilocybe cubensis, its circumtropical distribution is largely encouraged, if not caused, by the worldwide cattle ranching industry.
Because Psilocybe cubensis is intimately associated with cattle ranching, the fungus has found unique dispersal niches not available to most other members of the Strophariaceae family. Of particular interest is the cattle egret (Bubulcus ibis), a colonizer of Old World origin (via S. America), whose range of distribution overlaps much of that of Psilocybe cubensis. Cattle egrets typically walk alongside cattle, preying on insects; they track through spore-laden vegetation and cow dung, and transfer the spores to suitable habitat, often thousands of miles away during migration activities. This type of spore dispersal is known as zoochory, and it enables a parent species to propagate over a much greater range than it could achieve alone. The relationship between cattle, cattle egrets, and Psilocybe cubensis is an example of symbiosis -- a situation in which dissimilar organisms live together in close association.
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- Patouillard NT (1907). "Champignons nouveaux du Tonkin". Bulletin de la Société Mycologique de France (in French). 23 (1).
- Murrill, W.A. (May–June 1941). "Some Florida Novelties". Mycologia. 33 (3): 279–287. doi:10.2307/3754763. JSTOR 3754763.
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- "Breaking: Santa Cruz City Council Votes to Decriminalize Entheogenic Plants and Fungi". DoubleBlind Magazine. 2020-01-29. Retrieved 2020-01-30.
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- "Terence McKenna's books in print". Retrieved December 17, 2015.
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|Wikimedia Commons has media related to Psilocybe cubensis.|
- The Ones That Stain Blue Studies in ethnomycology including the contributions of Maria Sabina, Dr. Albert Hofmann and Dr. Gaston Guzman.
- Erowid Psilocybin Mushroom Vault
- Mushroom John's Tale of the Shrooms: Psilocybe cubensis (200 photographs and Description