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The Shroomverse alien by a slow river under moss-hung oaks in the Alabama countryside.

SPECIES ATLAS · PSILOCYBE

Psilocybe caerulescens

Named by Murrill, 1923

Psilocybin record: confirmed (several modern analyses)

A history of a name and a chemistry record, not an identification guide. No name, picture or description can show that a wild mushroom is safe, and poisonous mushrooms are mistaken for magic mushrooms. If someone may have eaten a wild mushroom, call a poison centre without waiting for symptoms: 1-844-POISON-X in most of Canada, 1-800-463-5060 in Quebec. Call 911 if they’re unconscious, not breathing or having a seizure.

How it was named.

Murrill published Psilocybe caerulescens in Mycologia 15(1): 20 in 1923, typified by a Burke collection from Alabama. Roger Heim later named Mexican varieties of it (mazatecorum and nigripes in 1957, albida and ombrophila in 1973). Species Fungorum now lists those varieties and eight later species names, among them P. weilii and P. caribaea, as synonyms.

Named
Murrill, 1923
Other names in the records
Psilocybe caerulescens var. mazatecorum R. Heim (1957), Psilocybe caerulescens var. nigripes R. Heim (1957), Psilocybe mixaeensis R. Heim (1959), Psilocybe caerulescens var. albida R. Heim (1973), Psilocybe caerulescens var. ombrophila R. Heim (1973), Psilocybe wrightii Guzmán (1978), Psilocybe heliconiae Guzmán, Saldarr., Pineda, G. García & L.-F. Velázquez (1994), Psilocybe weilii Guzmán, Stamets & F. Tapia (1997), Psilocybe villarrealiae Guzmán (1998), Psilocybe caribaea Guzmán, T.J. Baroni & Tapia (2003), Psilocybe bispora Guzmán, Franco-Mol. & Ram.-Guill. (2007), Psilocybe subannulata E. Horak & Guzmán (2009)
Type specimen
Alabama (Species Fungorum: typification Burke s.n.) (Species Fungorum record 259270; pin = Wikidata coordinates for Alabama (Q173))
Name record
Species Fungorum
The pin marks the type locality at the level of detail the record gives: one historical collection, not a range or a place to look. Land outlines: Natural Earth.

The psilocybin record.

Every analysis we could verify, oldest first, including results that found nothing. No amounts are given: they vary between collections and this is not a potency guide.

  1. 1958

    Reported Psilocybin reported by Heim & Hofmann (Comptes rendus 247: 557, 1958), as listed in Guzmán 1983 (Table 11); Guzmán notes the species had been studied chemically only once

    Method: not stated in the source we read. Guzmán 1983, The Genus Psilocybe (Beih. Nova Hedwigia 74), archive.org scan

  2. 2022

    Confirmed Psilocin and psilocybin detected, with baeocystin, in one collection (two fruiting bodies) documented by ITS sequencing

    Method: UHPLC-MS/MS. Gotvaldová et al. 2022, Int. J. Mol. Sci. 23: 14068

  3. 2025

    Reported Two cultivated strains confirmed as P. caerulescens by ITS were among 42 'psilocybin-producing' strains whose metabolomes were profiled; per-strain values are in supplementary data we did not open

    Method: HPLC-MS/MS metabolomics. Cohen et al. 2025, Sci. Rep. 15: 13822

What the record doesn’t show: The modern analysis covers a single collection of two fruiting bodies, and the 1958 report could not be opened; the GBIF total folds in many names now treated as synonyms.

Records on file.

GBIF, the global biodiversity database, held 1,010 occurrence records under this name, 0 of them from Canada, when we checked on October 25, 2026. Records include unverified observations and old misidentifications, so counts show where people have recorded the name, not where it grows.

See the name on GBIF

Sources

Compiled from the sources above; last checked .

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