How many psilocybin mushroom species are there? Why the counts run from about 45 to more than 300

The honest answer depends on what is being counted. A 2022 DNA study estimated that about 165 species belong to Psilocybe in the strict sense, but found that psilocybin had been measured in only about 45 accepted Psilocybe species (Bradshaw et al., 2022). Wider reviews that add other genera speak of at least 300 psychedelic mushroom species (Strauss et al., 2022). This page explains where each number comes from and why they will keep moving.

How many psilocybin mushroom species are there?

Each published figure answers a slightly different question. Some count every name ever placed in the genus Psilocybe. Some count species that turn blue when bruised, a reaction caused by psilocin breaking down, which researchers use as a sign that the compounds are probably there (Bradshaw et al., 2022). Only a few count species in which a laboratory actually found psilocybin. Our explainer on why magic mushrooms turn blue covers that reaction.

The spread is not a sign that anyone is wrong. A name database such as GBIF counts names its sources accept; on 25 October 2026 it listed 324 accepted species under Psilocybe and 49 under Deconica, the genus that took the non-bluing species (GBIF, Psilocybe; GBIF, Deconica). Those totals include many species that taxonomists now place in Deconica but that have not been formally moved (Bradshaw et al., 2022). Our species and names directory lists the best-known names with their records, our species atlas maps them, and our guide to names, species and strains explains why a strain name is not a species.

What did Gastón Guzmán count, and how did the numbers change?

Gastón Guzmán, the Mexican mycologist who described many Psilocybe species, published the first world monograph of the genus in 1983. He considered 467 names, accepted 144 species as valid, placed 90 names in synonymy, listed 119 as doubtful and excluded 114 (Guzmán, 1983). Of the 144, he counted 81 as hallucinogenic: 32 in Mexico, 26 in Central and South America, 18 in Canada and the United States, 13 in Australasia, 9 in Asia, 8 in Europe and one in Africa.

His monograph also shows how much earlier counts had swung. It notes that Singer reported about 84 species and varieties in 1975, and that Guzmán and Vergeer had listed 390 names in 1978, excluding 210 of them as belonging to other genera, as synonyms or as doubtful (Guzmán, 1983). Most of the reduction came from cleaning up names, not from losing mushrooms.

Guzmán updated his world count in a 2005 review in the International Journal of Medicinal Mushrooms (Guzmán, 2005). We could read only its bibliographic record, so we do not quote his 2005 total. A 2022 paper that cites it, alongside two reference works, gives a range of 277 to 326 known species for Psilocybe in the broad sense, of which 144 bruise blue (Bradshaw et al., 2022).

The larger “300-plus” figure for all psychedelic mushrooms comes from reviews that combine genera. One 2022 review cites a 1998 paper by Guzmán, John Allen and Jochen Gartz among the sources for “at least 300 species” across Psilocybe, Panaeolus, Pluteus, Gymnopilus and other genera (Strauss et al., 2022). That same sentence also lists Amanita, a genus whose psychoactive species contain different compounds, which shows how loosely the word “psychedelic” can be used in such totals. We did not open the 1998 paper.

Why did Psilocybe split into Psilocybe and Deconica?

By the late 2000s, DNA studies had shown that the old genus Psilocybe was two separate lineages: one with the bluing, psilocybin-producing species and one without. That created a naming problem. The species formally fixed as the type of the name, the moss-dwelling Psilocybe montana, belonged to the non-bluing group, so a strict split would have left the hallucinogenic species “without a generic name” (Norvell, 2009).

In 2007 six mycologists, with Scott Redhead as first author, proposed in the journal Taxon to conserve the name Psilocybe with P. semilanceata, the liberty cap, as its type, and to use the older name Deconica for the non-bluing group. The Nomenclature Committee for Fungi voted 13 to 0 to recommend it, as its report published in 2009 records (Norvell, 2009). Redhead worked for Agriculture and Agri-Food Canada in Ottawa, according to a 2010 paper he co-wrote (Norvell et al., 2010). Index Fungorum now marks Psilocybe as a conserved name with a conserved type (Index Fungorum).

Guzmán, a co-proposer, summed up the result in 2012: the bluing species stay in Psilocybe in the strict sense, and the non-bluing ones go to Deconica (Guzmán, 2012). The same year he and colleagues moved a non-bluing Thai species, P. deconicoides, into Deconica while describing four new bluing Psilocybe species from Thailand (Guzmán et al., 2012).

The paperwork has lagged. A 2022 review estimated that 52 species which probably belong in Deconica were still classified in Psilocybe, and noted that none of the non-bluing species is known to make psilocybin or psilocin (Bradshaw et al., 2022). Any total taken straight from a name database will therefore mix the two genera. For how one well-known species was named and renamed, see our P. cubensis naming history.

Which genera besides Psilocybe contain psilocybin?

A 2022 laboratory survey lists seven mushroom genera with psilocybin-producing members: Psilocybe, Panaeolus (including the former Copelandia), Pluteus, Gymnopilus, Pholiotina, Galerina and Inocybe (Gotvaldová et al., 2022). In each genus outside Psilocybe, only a small share of species is involved. The table below summarizes what the chemistry records we read actually show. It lists no amounts and does not compare strength.

Genus size puts this in proportion. GBIF listed 1,168 accepted species in Inocybe and 85 in Panaeolus on 25 October 2026 (GBIF, Inocybe; GBIF, Panaeolus). A 2013 review found psilocybin reported in only five European Inocybe species, all lacking muscarine, the toxin most of the genus is known for (Kosentka et al., 2013). The same paper’s introduction names six, which shows how even a single study can count the same group two ways.

Reports can also be withdrawn. Inocybe calamistrata was once reported to contain psilocybin, but later studies found none, and the original method was described as prone to false positives (Kosentka et al., 2013). The 2022 survey again found nothing in it, and found none in Panaeolina foenisecii, where earlier positive reports may reflect mix-ups with a different Panaeolus (Gotvaldová et al., 2022).

What did the 2020s genomic studies change?

They moved the question from “which mushrooms bruise blue” to “which carry the genes”. A 2018 study sequenced three distantly related psilocybin mushrooms (Psilocybe cyanescens, Gymnopilus dilepis and Panaeolus cyanescens), found the same gene cluster in each, and argued that it had jumped between fungal lineages by horizontal gene transfer (Reynolds et al., 2018). That explains why psilocybin turns up in scattered, unrelated genera.

The largest step was a 2024 study in PNAS. Its authors sequenced 71 fungarium specimens, including 23 type specimens, and built a family tree from 2,983 genes (Bradshaw et al., 2024). Only 52 specimens turned out to be true Psilocybe; 14 were Deconica. Before this work, the gene cluster was known from only five of about 165 Psilocybe species.

The 2024 study estimated that psilocybin production first arose in Psilocybe, about 67 million years ago at the earliest, and passed to other mushrooms four or five times between about 40 and 9 million years ago (Bradshaw et al., 2024). Its authors note that one of their datasets leaves open an earliest origin in Panaeolus instead. It also found two different gene orders matching a deep split in the genus, possibly a sign of two separate acquisitions. A 2025 paper added five more Psilocybe draft genomes (Bollinger et al., 2025).

Not everyone agrees on the timing. A 2026 preprint, not yet peer reviewed, found no psilocybin genes at all in Psilocybe fuscofulva, a non-bluing species that sits inside the genus, and dated the genus’s crown group to about 28 million years ago, against about 57 million years in the 2024 study (Slot et al., 2026). Species are also still being added: a 2025 Chinese study described a new bluing species, Psilocybe striata, and flagged at least six more undescribed taxa (Feng et al., 2025).

Why do so many listed species have only a few chemical analyses?

The gap is old. In 1983 Guzmán noted that one of the commonest Mexican hallucinogenic species had been studied chemically only once, that other common species had never been studied, and that no Japanese or tropical species had been analysed (Guzmán, 1983). Many species are rare, and a 2022 review notes that many have been collected only once (Bradshaw et al., 2022).

That review found psilocybin empirically identified in only about 45 accepted Psilocybe species, 32% of the roughly 140 bluing species (Bradshaw et al., 2022). It judged many older reports doubtful because the material was rarely kept as a voucher specimen that others could re-examine, some work was not peer reviewed, and methods varied. In its own test, very few stored P. cubensis specimens still had detectable psilocybin or psilocin, while most P. cyanescens specimens did, even after nearly 50 years.

Other reviews give other tallies of confirmed species: one cites earlier counts of 33 and 55 Psilocybe species testing positive, and a 2012 list of 146 species that either bruise blue or have a chemical confirmation (Strauss et al., 2022). Bluing is a useful hint but not a test: a 2022 survey found no tryptamines in two collections of Psilocybe species, P. fuscofulva and P. fimetaria (Gotvaldová et al., 2022). For what laboratory figures can and cannot show, see what lab studies establish about potency claims.

Names add a second layer of doubt. When the 2022 team checked fungarium specimens by DNA barcoding, they found names on specimens “largely unreliable, even at the genus level” outside a few well-known species (Bradshaw et al., 2022). A chemical result is only as good as the name on the sample it came from.

Does Canadian law depend on which species a mushroom is?

No. Schedule III of the federal Controlled Drugs and Substances Act lists psilocin and psilocybin as chemicals, and section 2(2) says a reference to a controlled substance includes any substance that contains one (Justice Laws, CDSA). The Act names no mushroom species, so a change in a species count does not change the law. Our guide to whether magic mushrooms are legal in Canada covers offences and exemptions.

What we don't know about the number of psilocybin species

• Guzmán’s own 2005 world total and the 1998 Guzmán, Allen and Gartz figures. We could not open either paper, so we report only how later authors cite them.
• How many of the roughly 140 bluing Psilocybe species really contain psilocybin. Most have never been tested with modern, voucher-based methods.
• How many names now filed under Psilocybe will move to Deconica, and how many more species are undescribed.
• When psilocybin production arose. The 2024 genome study and a 2026 preprint give very different dates, and the preprint has not been peer reviewed.
• How many species in Panaeolus, Gymnopilus, Pluteus and Pholiotina carry the gene cluster. Few have been sequenced, and Panaeolus has no molecular revision.

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