Psilocybe mexicana: the name, its type record and the 1958 psilocybin papers

Psilocybe mexicana sits at a crossing of two stories. It is a formally published species name with a type record. It is also the mushroom named in the title of the 1958 paper in which Albert Hofmann, Roger Heim and colleagues reported psilocybin. This guide follows the records for both, and is just as careful about the limits of those records. It does not describe the mushroom’s appearance, range or effects, and it cannot help you identify one.

It is one of several name-by-name guides in this collection. For the wider story of how psilocybin mushrooms came to Western science, see our history of magic mushrooms; for the compound itself, see what psilocybin is.

What is Psilocybe mexicana, and who named it?

Species Fungorum, the Royal Botanic Gardens, Kew name database that carries the same record as Index Fungorum, lists Psilocybe mexicana R. Heim, published in Revue de Mycologie, Paris, volume 22, issue 1, page 77, in 1957. Its record gives a holotype, specimen number PC 0085751, and the locality note “On ground in mountainous pastures: Oaxaca” (Species Fungorum). The record lists the name as current. Evidence: established, as a database record of a published name.

A holotype is the single specimen a name is permanently tied to. That is what “the name has a type record” means: if anyone asks what Psilocybe mexicana refers to, there is a preserved specimen and a publication to go back to. It does not tell you that any other mushroom, picture or product called “mexicana” is the same species.

The GBIF backbone, which aggregates names from several authorities, also treats Psilocybe mexicana as an accepted species and lists four other names as synonyms of it (GBIF; GBIF synonyms). We report that as what the database says. We did not assess the taxonomic reasoning behind it, and a database entry is not a substitute for the original descriptions.

What did the 1958 and 1959 papers report?

Three records form the early research trail. We read their bibliographic records and abstracts; we did not read the full papers, so we describe only what those records show.

• March 1958, Experientia 14(3): 107–109. Hofmann, Heim, Brack and Kobel, “Psilocybin, a psychotropic substance from the Mexican mushroom Psilocybe mexicana Heim” (the paper is in German; the title is as given in its record) (Hofmann et al., 1958).
• 1958, Comptes rendus de l’Académie des sciences 246: 1346–1351. Heim, Brack, Kobel, Hofmann and Cailleux. The indexed title (in an English rendering of the French original) concerns the formation of fruit bodies and sclerotia in culture of Psilocybe mexicana and the demonstration of psilocybin (Heim et al., 1958).
• 1959, Helvetica Chimica Acta 42(5): 1557–1572. Hofmann, Heim, Brack, Kobel, Frey, Ott, Petrzilka and Troxler. The abstract says the psychotropic principles of the Mexican hallucinogenic fungus Psilocybe mexicana Heim were isolated and obtained in crystalline form, named psilocybin and psilocin, and found in fruit bodies, in cultivated mycelium and in sclerotia (Hofmann et al., 1959).

That is a dated chemistry trail, and it is why this species name turns up in the history of psilocybin. Our history of magic mushrooms places these papers in their wider timeline, and what psilocybin is explains the compounds. Evidence: established for the dates, titles and the abstract’s wording.

What these records do not give us, because we did not read the full texts, is how the original material was collected and identified, or whether a voucher specimen from that material survives. Those details are what a specialist would need to check before saying exactly which material the 1958 chemists worked with.

A historical chemical report also answers a narrow question: which compounds were found in the material examined. It does not answer questions about clinical benefit, about modern samples sold or traded under a name, or about the long human relationship with these mushrooms. For how chemistry is separated from claims about experience or health, see how to research magic mushroom origin stories.

Does 1957 mean Psilocybe mexicana was “discovered” then?

No. 1957 is the publication date recorded for the scientific name (Species Fungorum). Saying a scientist described a species is narrower than saying he discovered it, and the stronger word can erase other kinds of knowledge. Scientific description and cultural history are different histories, and the name’s date belongs only to the first.

We do not assign a ceremonial tradition to this species, identify an ancient image as this species, or let one famous encounter stand in for many communities. We did not find sources that would let us make such statements responsibly in a taxonomy article. A fuller cultural account would need primary historical material and appropriate cultural expertise, with clear attribution. Our history of magic mushrooms and our guide to María Sabina follow that wider record with sources.

Does every “Mexicana” label mean Psilocybe mexicana?

No, and one published table shows why. Cohen and colleagues (2025) compared 42 psilocybin-producing strains grown under the same conditions. Because species names assigned from morphology “may be unreliable”, they cross-checked all 42 by sequencing a stretch of DNA called the internal transcribed spacer (ITS) (Cohen et al., 2025).

Row 38 of their Table 1 lists genus Psilocybe, species tampanensis, strain “Mexicana”, ITS classification Psilocybe tampanensis (99.44% identity, 96% query cover), GenBank accession PV069816 (Cohen et al., 2025). In the text, the authors write that mexicana, galindoi and tampanensis were identified as tampanensis. In the table, “Mexicana” is a strain name, not a species finding.

This is a result for one sample. It does not show that Psilocybe mexicana and Psilocybe tampanensis are the same species, and the paper does not make that claim. GBIF currently lists the two as separate accepted names (GBIF, P. mexicana; GBIF, P. tampanensis). The same GBIF synonym list for P. mexicana includes Psilocybe galindoi, a name whose two strains in the 2025 table were also classified as P. tampanensis. We report both facts as they stand and do not try to reconcile them: databases and sequence results can disagree, and sorting that out is a specialist task.

The practical lesson is to keep the original label and the study’s identification side by side, and never merge them. For the other name, see Psilocybe tampanensis: the original record and the naming; for the same pattern with another label, see why “Blue Meanies” is an ambiguous name. The broader guide is magic mushroom names, species, strains and varieties.

What does this page leave out, and why?

Appearance, range and growth habit. A morphological summary should be checked against the primary taxonomic treatment, and we have not done that, so we give no dimensions, distribution claims or identification features. We also do not describe effects: early chemical importance does not establish a modern effects profile for the species, or for any product that carries its name.

Wikidata keeps a separate item for the species (Wikidata), which can help when you need to tell the species apart from a label with the same word. It is a pointer to other records, not evidence of identity.

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