Psilocybe cyanescens: taxonomy, reference specimens and the naming confusion

Search for “cyanescens” and you will find at least two unrelated scientific names sharing one word. This guide separates them, explains what the reference specimens attached to Psilocybe cyanescens are (and are not), and says where this site deliberately stops. It covers names and the record, not identification.

What is Psilocybe cyanescens, taxonomically?

It is a species in the genus Psilocybe. The Species Fungorum name record, which mirrors the Index Fungorum database kept at the Royal Botanic Gardens, Kew, lists the name as Psilocybe cyanescens Wakef., published in Transactions of the British Mycological Society 29(3): 141 (1946), and marks it as the current name (Species Fungorum). The Global Biodiversity Information Facility (GBIF) shows the same publication details and an accepted status (GBIF), and Wikidata gives the same author and year (Wikidata).

The “Wakef.” after the name is the standard abbreviation for the author who published it, here E. M. Wakefield. Higher classification differs between databases: Species Fungorum places the genus in the family Agrocybaceae, while GBIF and Wikidata place it in Hymenogastraceae (Species Fungorum; GBIF; Wikidata). That is one reason this page sticks to genus and species names, which the sources agree on.

Is Psilocybe cyanescens the same as Panaeolus cyanescens?

No. They are separate names in different genera. The first word of a scientific name is the genus and the second is the species epithet within that genus, so the same epithet can appear in unrelated genera without the two being synonyms. Species Fungorum records Panaeolus cyanescens Sacc. (Syll. Fung. 5: 1123, 1887), and the synonyms it lists are Agaricus cyanescens Berk. & Broome (1871) and Copelandia cyanescens (Sacc.) Singer. No Psilocybe name appears among them (Species Fungorum, Panaeolus cyanescens).

Our separate reference on the other name is Panaeolus cyanescens and Copelandia. A further layer of ambiguity sits in the common name: see why “Blue Meanies” is an ambiguous name. When a comparison involves both species, spell out the full names rather than abbreviating both to “P. cyanescens”.

What are the holotype and epitype of Psilocybe cyanescens?

The name record lists a holotype, K(M) 63976, and an epitype, PRM 901481 (Species Fungorum). The 2012 paper that designated the epitype gives the fuller records (Borovička, Rockefeller and Werner, 2012):

• Holotype: a collection from the Queen’s Cottage grounds at the Royal Botanic Gardens, Surrey, England, dated 25 October 1911 and collected by E. M. Wakefield, held at Kew as K(M) 63976.
• Epitype (designated in that paper): a collection from the Klein Flottbek Botanical Garden in Hamburg, Germany, dated 26 November 2003 and collected by Jürgen Hechler, held as PRM 901481. The paper lists three GenBank sequence accessions for it: GU565175, GU565167 and GU565158.

The prefixes are herbarium codes for the institutions that keep the specimens. In practice, these identifiers give researchers a route to the exact reference material behind the name. They are record numbers, not a description of the species, and this page does not infer anything about identification from them.

What is an epitype, and is it a new strain?

No, it is not a strain or a product name. A holotype is the single specimen or illustration on which a species name is based (International Code of Nomenclature, Art. 9). An epitype is chosen later, as an interpretative type, when the original type material is demonstrably ambiguous and cannot be critically identified well enough to apply the name precisely (same Article). It does not turn earlier specimens into a different species.

That fits this case. The 2012 authors describe the holotype as very old and in bad condition, state that it belongs to P. cyanescens in the strict sense, and designate an epitype characterized by DNA data “to avoid further confusion” (Borovička, Rockefeller and Werner, 2012). The exact role of any later reference specimen should be read in the taxonomic treatment that designates it, not guessed from the catalogue number.

Why does the 2012 Psilocybe allenii paper matter for this name?

The paper that designated the epitype was primarily a description of a different species, Psilocybe allenii, from the Pacific Coast of the USA (Borovička, Rockefeller and Werner, 2012). The authors report that it is closely related to P. cyanescens, that some microscopic features of the two overlap, and that they separate the new species using a gross feature plus its ITS rDNA sequence. They also report sequences from the P. allenii holotype and paratypes. We have deliberately left out the feature details: they are the part of the treatment that needs specialist review.

GBIF currently lists Psilocybe allenii as an accepted name (GBIF). The authors also close by saying more work is needed on how species in this complex are delimited, and that future molecular and possibly other results might lead to new concepts (Borovička, Rockefeller and Werner, 2012). For a general reader the point is methodological: a familiar name and an outward resemblance do not replace a documented species comparison. Such comparisons can rest on microscopy, sequence data and reference collections that a photograph cannot supply.

The same paper notes that P. cyanescens was described from Kew Gardens, and it discusses a hypothesis from earlier work by Borovička that the species was introduced to Europe and is native to North America (Borovička, Rockefeller and Werner, 2012). We report that as a hypothesis the authors cite, not as settled history.

What can a species name or a type record not tell you?

• Whether a particular mushroom, photograph or product is that species. A type record is not an identification tool.
• How strong any mushroom is. Taxonomic confidence does not fix a chemical concentration; a lab result needs its own sample description and method. See what lab studies do and do not establish.
• Whether a mushroom is safe. A name is not a safety test.
• Anything about a Shroomverse product. Our site uses several product names that echo mushroom names, and a product label is not evidence that any specimen in a record is the material sold.

Photographs deserve the same caution. A descriptive image is only evidence if the specimen identity, the caption and the image rights are verified; a stock photo chosen because it resembles a popular online example is not. That is why this reference shows none. For the wider map of names, see our directory of magic mushroom species and names, and for the colour-change chemistry see why magic mushrooms turn blue.

What this page does not settle

• The full morphological and microscopic treatment from the 2012 paper. Held back until a specialist has reviewed it (not covered).
• The current family-level placement. Databases disagree (unresolved).
• Where P. cyanescens is native. The authors present a hypothesis (unresolved).
• Whether future molecular work will redraw the boundary between P. cyanescens, P. allenii and relatives. The authors expect more work to be needed (unresolved).

Shroomverse sells mushroom products. This article is general information about mushroom names and taxonomy. It is not medical, legal or identification advice, and it does not recommend any product.