A postdoc in Massachusetts. A museum curator in Zimbabwe. Two dried specimens — one collected in 1995, the other in 2011. And a DNA test that rewrote 42 years of assumption about where the world's best-known "magic mushroom" came from. This is why species names matter, why what a mushroom looks like isn't always what it is, and what the biology of a single genus quietly tells us about the biology of everything else.
Short answer
A team led by Alexander Bradshaw at Clark University published a 2024 preprint that describes a new species of psychoactive fungi — Psilocybe ochraceocentrata — as the closest known wild relative of the domesticated Psilocybe cubensis. DNA sequencing on specimens collected across Africa dates the two species' last common ancestor to roughly 1.5 million years ago, long before humans domesticated cattle and long before modern humans existed. The finding is the first empirical support for a 1983 hypothesis by Gastón Guzmán that the cubensis lineage was originally African. The broader story — and the reason it matters far beyond a single species discovery — is that DNA authentication reliably separates species that look identical to the eye, and species with different DNA have different chemistry. In fungi, as in most of biology, morphology is a first draft. DNA is the edit.
The specimens from Zimbabwe
Cathy Sharp is a mycologist at the Natural History Museum of Zimbabwe. In 1995, she collected a mushroom in Zimbabwe. In 2011, she collected another in South Africa. Both looked, at a glance, like Psilocybe cubensis — the species that has been the reference point for magic mushroom biology since it was formally described from Cuba in 1904, and which by 2025 was cultivated commercially and studied academically across dozens of countries.
Both specimens sat in the museum collection for years, catalogued and stored. In the way that most museum specimens do.
Then Sharp sent them to Alexander Bradshaw — a postdoctoral researcher in the biology department at Clark University in Worcester, Massachusetts, working in the lab of David Hibbett and Javier Tabima Restrepo. Bradshaw's work focuses on the genus Psilocybe specifically: how many species there are, how they're related to each other, and how the chemistry that makes them "psychoactive" evolved.
When the DNA came back, the two specimens were unlike anything already in the database. Similar to P. cubensis. But not the same.
160 species, seven of them African
There are roughly 160 identified species of Psilocybe worldwide. The number is fuzzy at the edges because taxonomic work in fungi has been chronically under-resourced — most of what we know about mushrooms globally comes from Europe and the coasts of the United States, with pockets of intensive study in Mexico, Australia, New Zealand, and parts of Southeast Asia. When Bradshaw ran the two African specimens against the global database, one thing was immediately clear: of those ~160 species, only seven had ever been formally documented from the entire African continent.
That number is almost certainly not because Africa is fungus-poor. It's because the mycological community has spent most of the last century looking somewhere else.
"We don't have a good understanding of the global diversity of fungi," Bradshaw told Clark's news office in April 2025. "If you were to make a map of known species and where they are from, the vast majority are from Europe and the coasts of the United States." The African fungal biota — like most tropical and subtropical fungal biotas — remains a substantial blank spot.
So Bradshaw's first job was to rule out the possibility that Sharp's Zimbabwe and South Africa specimens were just one of the seven previously described African Psilocybe species. He ran genetic and genomic sequencing on the samples and compared them against every known species from Africa and closely related species from Asia. In every test, the signal was the same: the specimens were something new.
The team named the new species Psilocybe ochraceocentrata — the Latin for the ochre-coloured center of the mushroom's cap, the visible feature that most reliably distinguishes it from cubensis's uniform golden-brown crown.
Morphological plasticity, or: why looks aren't enough
This is where the story turns from "new species discovered" into "a general principle of biology worth understanding."
The reason P. ochraceocentrata was previously overlooked isn't that no one had ever picked one up. Bradshaw suspects that many ochraceocentrata specimens are already sitting in museum drawers around the world, labelled as P. cubensis. "I think that these are very common, but because they look very similar to Psilocybe cubensis, people probably wrote them off as cubensis, which makes perfect sense."
The technical term for this is morphological plasticity: the phenomenon where a single species can look meaningfully different depending on where and how it grew, and where two genuinely distinct species can look nearly identical. Body size, cap colour, stem length, gill spacing, spore print — all the features a field guide instructs you to check — can vary substantially inside a species, and can overlap between species. Morphology is often reliable for genus. It's often reliable for the well-studied common species. It becomes unreliable exactly where taxonomy matters most: at the boundaries between closely related species.
Bradshaw's group made this argument explicitly in a 2022 paper in Applied and Environmental Microbiology, where they DNA-tested Psilocybe specimens across major herbaria (mushroom museums) and reported "widespread misdeterminations" — museum specimens routinely labelled as one species were, on DNA sequencing, actually another species. The taxonomic accuracy of the historical Psilocybe collection is poor except for a few well-known species. What everyone had been calling cubensis included, at least sometimes, things that weren't cubensis.
That paper's second finding is arguably more important: two specimens labelled the same species can have very different chemistry. The alkaloid profile — the mix and concentration of psilocybin, psilocin, baeocystin, aeruginascin, and related molecules — varies between correctly identified specimens of the same species, and varies again between species that had been confused with each other. If you don't know what species you actually have, you don't know what chemistry you actually have.
This is the core Bradshaw thesis, and it's the reason the ochraceocentrata discovery matters beyond the immediate news value: DNA authentication is the only reliable way to know what species you have. Species is the only reliable way to know what chemistry you have.
The Guzmán hypothesis, forty-two years later
The other reason the discovery matters is historical. In 1983, the great Mexican mycologist Gastón Guzmán — the person who described more Psilocybe species than anyone before or since — proposed that the domesticated P. cubensis lineage was originally African, and had spread to the Americas around 1500 CE, inadvertently, on the back of the same cattle-transport that carried European colonialism. The idea sat as an educated guess for four decades. No one had the tools to test it.
Bradshaw's team tested it. Using DNA sequences from every accessible African Psilocybe type specimen, plus the newly discovered ochraceocentrata material, they ran multi-locus phylogenetic analysis (comparing many genes at once to reconstruct the family tree) and molecular clock estimation (calibrating that tree against known divergence rates to date each split).
The last common ancestor of P. cubensis and P. ochraceocentrata dates to approximately 1.5 million years ago, with a 95% credibility interval spanning 710,000 to 2.55 million years. Even at the youngest end of that range, the split predates the domestication of cattle (approximately 10,500 years ago) by two orders of magnitude. It predates the origin of modern humans (approximately 300,000 years ago) by another order of magnitude entirely.
Whatever cattle did in 1500, they weren't responsible for the cubensis-ochraceocentrata split. The two species were already distinct while our ancestors were still figuring out fire.
The ecological modeling adds a second layer. The team ran bioclimatic niche modeling for both species — mapping the environmental conditions where each fungus is likely to occur — and projected that map back over the last three million years. The result: probable historical presence across Africa, Asia, and the Americas. Cubensis's spread wasn't a single cattle-borne trip in 1500. It was a slow, distributed movement over deep geological time, following the herbivore dung it depends on across continental land bridges and inter-continental grasslands.
So Guzmán's hypothesis was directionally right — the lineage did originate in Africa — but the mechanism he proposed was wrong. The story is older and slower than 1500 CE, and it involves biology at scales that the human story is just a footnote to.
What this tells us about the science, generally
Three lessons worth generalising from the discovery, none of them specific to Psilocybe.
1. Museum collections still generate discoveries. The two specimens that anchored this paper sat in a museum for years — one for nearly three decades — before the DNA sequencing tools existed to describe them properly. The discovery didn't need new fieldwork. It needed new methods applied to old material. Any serious biological collection is, in a real sense, a compressed archive of un-described species waiting for the right instruments.
2. Morphology is a starting hypothesis, not a conclusion. Fifty years ago, a mushroom that looked like cubensis was, functionally, called cubensis. In 2024, we can say that a mushroom that looks like cubensis is a hypothesis to be tested. This applies well beyond mushrooms. It applies to plants, to insects, to bacteria, to fish, to most of the biological world. The difference between what things look like and what they are turns out to be one of the most productive gaps in modern biology.
3. Species matter because chemistry follows them. The point Bradshaw's 2022 paper made, that the ochraceocentrata discovery reinforces, is that specimens labelled as the same species can have different chemistry, and specimens labelled as different species can have chemistry that matters differently. If your goal is to know the chemistry — for research, for medicine, for anything — you need to know the species. And in most of the biological world we don't know the species yet.
This is quiet science. It doesn't produce a headline chemical, a headline therapy, or a headline product. What it produces is the ground on which those things become possible. It's the kind of work that lets everything else be a little more honest.
FAQ
Is Psilocybe ochraceocentrata a psychoactive species?
It's in the Psilocybe genus, which as a family carries the psilocybin-producing biosynthetic gene cluster. Beyond that, the specific chemistry of ochraceocentrata remains under active study. The Bradshaw group's 2024 PNAS work on Psilocybe phylogenomics established that the psilocybin gene cluster has independent origins across the genus, which means "being in Psilocybe" is not by itself a reliable predictor of chemistry.
Where does ochraceocentrata grow?
Confirmed collections are from Zimbabwe and South Africa. Ecological modelling suggests historical presence across Africa, Asia, and the Americas over the last three million years — but the current documented range is limited to sub-Saharan Africa.
Why does the "1.5 million years ago" number matter?
It rules out the assumption that cubensis was distributed by human agricultural activity. The genus's biogeography is a deeper story than the human story, which is worth remembering whenever we're tempted to write history at ourselves.
Are there more Psilocybe species still undescribed?
Almost certainly, yes. Bradshaw suspects that Africa alone likely holds several undescribed Psilocybe species that are currently hidden in museum specimens labelled as cubensis. The 160-species total for the genus is likely a substantial under-count.
How solid is the ochraceocentrata paper, given it's a preprint?
The preprint is at bioRxiv and has not been peer-reviewed at the time of this writing. That's the appropriate caveat. However: the paper is by an established research group (Bradshaw, Dentinger, and collaborators, whose Psilocybe work has been peer-reviewed in PNAS and Applied and Environmental Microbiology), the methods (multi-locus phylogeny, molecular clock analysis, ecological niche modelling) are all standard, and the P. ochraceocentrata species has been cited by subsequent papers and mentioned in Paul Stamets' 2025 book. It is best treated as a strong preprint likely to survive peer review largely intact.
Continue reading
- Beta-Glucans: The Compound Family Behind Mushroom Immune Activity — the chemistry-first framing this piece extends.
- Are Mushroom Supplements Actually Worth It? — the "species matter" argument applied to the everyday supplement decision.
- Turkey Tail: Beta-Glucans and Immune Intelligence — an example of species-level chemistry variation in a well-studied edible mushroom.
- How to Read a MYKO Label — the practical version of "why species names matter."
References
- Bradshaw AJ, Sharp C, Van Der Merwe B, Tremble K, Dentinger BTM. Discovery of the closest free-living relative of the domesticated "magic mushroom" Psilocybe cubensis in Africa. bioRxiv, 2024. doi.org/10.1101/2024.12.03.626483
- Bradshaw AJ, Ramírez-Cruz V, Awan AR, et al. Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster. Proceedings of the National Academy of Sciences, 2024.
- Bradshaw AJ, Backman TA, Ramírez-Cruz V, et al. DNA Authentication and Chemical Analysis of Psilocybe Mushrooms Reveal Widespread Misdeterminations in Fungaria and Inconsistencies in Metabolites. Applied and Environmental Microbiology, 2022.
- Guzmán G. The genus Psilocybe: A systematic revision of the known species including the history, distribution and chemistry of the hallucinogenic species. Nova Hedwigia, 1983.
- Hanson M. Discovering a "magic" mushroom was no trick. Clark University News, April 1, 2025. clarku.edu