Psilocybe is a large, globally distributed genus of mushrooms, many of which produce psilocybin — but how many species it contains, and how they relate to one another, is genuinely unsettled. Estimates run from roughly 165 to more than 300 named species depending on the definition, and the most extensive genetic study to date still called the phylogeny and taxonomy substantially incomplete. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 Potency differs widely across species, [2] Peer-reviewed Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids doi:10.3390/ijms232214068 which is why species identity is the first thing that sets a mushroom’s broad potency range. This is a biology overview, not an identification key: it contains no features for telling species apart, because deadly lookalikes exist and wild identification is hazardous.
This is an evidence and biology review, not sourcing, foraging, or cultivation guidance. Psilocybin mushrooms are controlled in most jurisdictions, deadly lookalikes exist, and potency varies widely. Nothing here is instructions for finding, identifying, growing, storing, or dosing them.
A large genus that resists a clean count
The genus Psilocybe is not a tidy list. In its traditional sense it has been said to contain somewhere between about 165 and over 300 named species, and even that range depends on which definition of the genus is used. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 A subset of these — the “bluing” species, which discolor when damaged — are generally associated with psilocybin, but only a fraction of the genus has been examined with modern molecular tools, and chemical data exist for a still smaller portion. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 The honest headline is that the boundaries of the genus, and the membership of the psilocybin-producing club within it, are still being worked out.
This matters for research literacy because confident statements about “Psilocybe species” often assume a stability the science does not have. When sources, vendors, or enthusiasts speak about a named species as if its identity and properties were fixed, they are frequently standing on taxonomy that experts are actively revising.
The taxonomy is contested — and recently redrawn
For much of its history the genus was sorted by visible features and by the bluing reaction. Molecular phylogenetics complicated that picture: it showed that the traditional genus is not a single natural group, and that the application of many long-used names is uncertain. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 A 2024 phylogenomic analysis built the most complete dataset assembled for the genus, using thousands of gene families and dozens of reference specimens, and still concluded that much remained unresolved — while also revealing a deep evolutionary split within the genus and showing that the genetic machinery for making psilocybin has been shuffled around evolutionary history rather than inherited in one simple line. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121
The take-home is not the phylogenetic detail but its consequence: a name is not a guarantee. If the scientific names themselves are unstable, then any downstream claim that hangs on species identity — including potency claims and “strain” claims — inherits that instability. This is one reason the strains article treats cultivar names with such skepticism.
Potency is a species-level property — among others
Across species, psilocybin content varies a great deal, and that variation begins at the level of the species before strain, flush, or storage effects are layered on. [2] Peer-reviewed Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids doi:10.3390/ijms232214068 Published measurements have reported higher alkaloid concentrations in some species than others, and the chemically defined effects of psilocybin itself — its action at the serotonin 5-HT2A receptor — are the same regardless of which species delivered it. [3] Peer-reviewed Psychedelics doi:10.1124/pr.115.011478 Two cautions belong with any such ranking, though: potency remains sample-dependent, so a species-level tendency does not fix the content of an individual specimen, and a species name is not by itself a potency measurement. In other words, the species changes how much active compound is typically present, not what that compound does.
It is worth being precise about what this does and does not imply. It does not mean that knowing a species lets someone predict a dose: within any species, potency still varies by strain, by flush, and by storage, as the potency variability article lays out, and a single controlled grow can shift severalfold between harvests. [4] Peer-reviewed Variation of psilocybin and psilocin levels with repeated flushes (harvests) of mature sporocarps of Psilocybe cubensis (Earle) Singer doi:10.1016/0378-8741(82)90014-9 Species identity sets a broad range; it does not pin down a number.
| Question | Answer at the species level |
|---|---|
| Does it contain psilocybin? | Often, for bluing Psilocybe species — but not universally, and not always tested |
| What does the psilocybin do? | The same thing regardless of species: it becomes psilocin and acts on 5-HT2A |
| What is the broad potency range? | Set partly by species; some are far more potent than others |
| What is the exact dose in a given mushroom? | Not determinable from species alone; strain, flush, and storage all intervene |
Why this article carries no identification information
A page about a genus that includes a controlled, psychoactive organism — and whose members can be confused with deadly mushrooms — is a place to be especially careful. Naming a species and identifying a mushroom are different tasks: this article discusses the genus at a research level and deliberately omits field marks, habitat cues, spore descriptions, and every other detail that identification would require. This overview deliberately contains no distinguishing features, no habitat or seasonal guidance, no spore-print or microscopy detail, and nothing else that could function as an identification key. The reason is covered directly in identification risk and lookalikes: misidentification of wild mushrooms can be fatal, and the responsible conclusion from the biology is that wild identification should be left to mycologists, not attempted from an article.
- An uncertain count
- Estimates of the genus range from roughly 165 to over 300 species, and much of it is chemically and genetically unexamined. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121
- Unstable taxonomy
- The traditional genus is not a single natural group; names and relationships are still being revised, so species identity is not a fixed anchor. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121
- Species sets the range, not the dose
- Species identity influences the broad potency range but does not determine a specific dose, which strain, flush, and storage further alter. [2] Peer-reviewed Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids doi:10.3390/ijms232214068
- Same compound, different amounts
- Whatever the species, the psilocybin it contains acts identically; only the quantity differs. [3] Peer-reviewed Psychedelics doi:10.1124/pr.115.011478
Frequently asked questions
How many psilocybin-containing species are there?
There is no single agreed number, which is itself part of the story. Estimates for the genus Psilocybe in its traditional sense range from roughly 165 to over 300 named species depending on how the genus is defined, and only a portion of these have been studied with modern molecular methods. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 Many — though not all — of the blue-bruising species are thought to contain psilocybin, but a great deal of the genus has never been chemically analyzed. So “how many” is an open question, not a settled fact.
Do different species differ in potency?
Yes, substantially. Psilocybin content is a property of the species (and then of the individual mushroom, the strain, and the conditions), and the spread across species is wide. [2] Peer-reviewed Extensive Collection of Psychotropic Mushrooms with Determination of Their Tryptamine Alkaloids doi:10.3390/ijms232214068 This is one reason species identity matters before any other potency consideration. But knowing that species differ in potency is a biological observation, not a sourcing or selection guide, and this article gives no features for telling species apart.
Is the taxonomy of Psilocybe settled?
No. Molecular work has shown that the traditional genus is not a single natural group, the application of many names is uncertain, and the relationships within it are still being revised. A 2024 phylogenomic study assembled the most extensive dataset to date and still described the phylogeny and taxonomy as substantially incomplete. [1] Peer-reviewed Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster doi:10.1073/pnas.2311245121 So the names themselves are a moving target, which compounds the difficulty of making confident claims about any particular species.
Can this help me identify a Psilocybe mushroom?
No, and that is deliberate. This article describes the genus at the level of biology and research — how many species there may be, that potency differs, that the taxonomy is contested. It contains no identifying features, habitat or season guidance, spore or microscopy information, or anything that functions as a key. Deadly lookalikes exist, and the only safe conclusion this overview supports is that wild identification is hazardous and not something to attempt from a web page.