How many species contain psilocybin?
There's no single agreed number, because counts depend on how species are defined and whether psilocybin has actually been measured or only inferred.
- A 2005 survey by the Mexican mycologist Gastón Guzmán accepted 227 taxa in the genus Psilocybe, of which 144 were known to be hallucinogenic. Mexico had the most of any country, with 53; the United States and Canada together had 22, and Europe 16.1
- A 2024 genetic study works with roughly 165 Psilocybe species and concludes that the ability to make psilocybin arose first in Psilocybe and later spread to other mushroom groups.3
- The EU's drugs agency gives a more conservative figure of more than 50 species.4
Psilocybin has been found in at least eight genera: Conocybe, Galerina, Gymnopilus, Inocybe, Panaeolus, Pholiotina, Pluteus and Psilocybe.2 Several of those genera also contain deadly species, which is one reason identification matters so much.
Six well-known species compared
Potency below is described in words, based on published measurements. Every species varies widely from one mushroom to the next.6
| Species | Common name | Grows on | Where | Relative potency |
|---|---|---|---|---|
| Psilocybe cubensis | Often just "cubensis" | Dung and rich pasture | Tropics and subtropics worldwide2 | Moderate and variable; the species behind most cultivated strains2,6 |
| Psilocybe semilanceata | Liberty cap | Grassland and pasture | Temperate Northern Hemisphere, especially Europe6 | Typically high in psilocybin6 |
| Psilocybe cyanescens | Wavy cap | Wood chips and mulch | U.S. Pacific Coast; introduced to Europe6 | "One of the most potent" species measured6 |
| Psilocybe azurescens | None widely used | Woody debris and coastal dune grasses | A narrow range around the Columbia River delta, Oregon and Washington7 | Highly potent6 |
| Psilocybe mexicana | None widely used | Grassy and mossy ground | Mexico, Guatemala, Costa Rica2 | Moderate; the species Albert Hofmann first isolated psilocybin from6 |
| Panaeolus cyanescens | None widely used | Dung5 | Reported across tropical regions worldwide and parts of the U.S.13 | High; reported higher than many Psilocybe species5 |
The lookalikes that kill
Never eat a wild mushroom unless an identification expert has confirmed it. Some of the most dangerous mushrooms in North America grow in the same places as psilocybin species.
- Amatoxins cause about 95% of deaths from mushroom poisoning worldwide. They damage the liver, and symptoms can be delayed for many hours, by which point serious harm may already be under way.8,10
- Galerina marginata, the deadly galerina, grows on rotting wood, including wood chips in parks and gardens, the same habitat as the wavy cap. Its toxins aren't destroyed by cooking. One difference is spore color: reddish brown for Galerina, dark purplish brown for Psilocybe.9,2
- Pholiotina and Conocybe species also contain amatoxins and grow in lawns, mulch and compost.8,5
- Cooking, drying or soaking doesn't remove these toxins.11
If someone may have eaten a poisonous mushroom, call Poison Control at 1-800-222-1222 right away, even before symptoms start. Call 911 if they collapse, have a seizure or have trouble breathing.10,11
Even experts get it wrong. When researchers DNA-tested 94 museum specimens labeled as psilocybin mushrooms, they found the identifications "largely unreliable, even at the genus level."12
Why bluing isn't a reliable test
Many psilocybin mushrooms turn blue where they're bruised or cut. It's a well-known sign, but it can't be used to rule a mushroom in or out: in some hallucinogenic species the bluing is hard to see, and a blue tint says nothing about whether a deadly species is in the same handful.1
Species profiles
- Liberty cap (Psilocybe semilanceata): Europe's most common psilocybin mushroom, and the species this domain's original Norwegian community was built around.
- Psilocybe cubensis: the tropical dung-loving species behind almost every named strain.
For what's known about strains of P. cubensis, see our strain guide.
Sources
- Guzmán G. Species diversity of the genus Psilocybe in the world mycobiota, with special attention to hallucinogenic properties. International Journal of Medicinal Mushrooms 2005;7(1-2):305-331. bibliography.maps.org
- Van Court RC et al. Diversity, biology, and history of psilocybin-containing fungi. Fungal Biology 2022;126(4):308-319. doi:10.1016/j.funbio.2022.01.003. doi.org
- Bradshaw AJ et al. Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster. PNAS 2024;121(3):e2311245121. doi:10.1073/pnas.2311245121. doi.org
- European Union Drugs Agency (EUDA), drug profile: hallucinogenic mushrooms. euda.europa.eu
- Strauss D et al. An overview on the taxonomy, phylogenetics and ecology of the psychedelic genera Psilocybe, Panaeolus, Pluteus and Gymnopilus. Frontiers in Forests and Global Change 2022;5:813998. doi:10.3389/ffgc.2022.813998. doi.org
- Gotvaldová K et al. Extensive collection of psychotropic mushrooms with determination of their tryptamine alkaloids. International Journal of Molecular Sciences 2022;23(22):14068. doi:10.3390/ijms232214068. doi.org
- Wikipedia, "Psilocybe azurescens" (secondary source; cites Stamets 1996 and Guzmán, Allen & Gartz 1998). en.wikipedia.org
- Horowitz BZ, Moss MJ. Amatoxin Mushroom Toxicity. StatPearls. pubmed.ncbi.nlm.nih.gov
- UBC Beaty Biodiversity Museum, Galerina marginata. explore.beatymuseum.ubc.ca
- Poison Control (National Capital Poison Center), "Mushroom poisoning: Don't invite 'the death angel' to dinner." poison.org
- California Poison Control System, magic mushroom safety. calpoison.org
- Bradshaw AJ et al. DNA authentication and chemical analysis of Psilocybe mushrooms reveal widespread misdeterminations in fungaria and inconsistencies in metabolites. Applied and Environmental Microbiology 2022;88(24):e0149822. doi:10.1128/aem.01498-22. doi.org
- Wikipedia, "Panaeolus cyanescens" (secondary source). en.wikipedia.org