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PSILOCYBIAA monograph for the digital age.
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Psilocybia / The Index / Species record

The Psilocybe Index / Species account

Psilocybe samuiensis

Guzmán, Bandala & J. W. Allen

Taxonomy: acceptedChemistry: Not yet researchedMolecular data: Not yet researched

Scoped agent source check; no human scientific review. Original 1993 description, comprehensive synonymy, chemistry, molecular literature, conservation, scientific imagery and occurrence datasets remain unchecked. Source-specific morphology and collection-label differences are retained without resolution.

01Overview

Agent source-checked

This scoped account compares two published treatments of the Thai holotype, covering selected morphology, habitat and collection provenance. Original-description coverage and the broader literature review remain incomplete. [ramirez-cruz-2013-types] [guzman-2012-thailand]

This is a scientific reference record, not field-identification guidance.

02Nomenclature

Accepted name
Psilocybe samuiensis
Authority
Guzmán, Bandala & J. W. Allen
Family
Agrocybaceae
Publication year
1993
Basionym
Not yet researched — verification required
Taxonomic status
accepted
MycoBank identifier
Not yet researched — verification required
Index Fungorum identifier
Not yet researched — verification required
Synonyms (0 recorded names)

No verified synonyms entered. This does not indicate that synonyms do not exist.

Nomenclatural sources: [gbif-5459370-2026] [ramirez-cruz-2013-types] [guzman-2012-thailand] [niskanen-2026]

Research completeness

taxonomy
Agent source-checked — Codex (agent), 2026-09-14

Name and primary type treatment checked; family classification reconciled. Comprehensive synonymy review remains pending.

overview
preliminary

Selected passages checked; coverage is incomplete.

description
preliminary

Selected passages checked in the 2012 treatment and 2013 holotype revision. Coverage remains incomplete; measurements and collection labels retain their source-specific notation.

ecology
preliminary

Selected passages checked in the 2012 treatment and 2013 holotype revision. Coverage remains incomplete; measurements and collection labels retain their source-specific notation.

distribution
disputed

Selected passages checked in the 2012 treatment and 2013 holotype revision. Coverage remains incomplete; measurements and collection labels retain their source-specific notation.

chemistry
not researched

Not researched for this account; no absence claim.

molecular
not researched

Not researched for this account; no absence claim.

history
preliminary

Selected passages checked; coverage is incomplete.

conservation
not researched

Not researched for this account; no absence claim.

03Taxonomic description

Taxonomic description. These characters are presented for scientific reference and are not intended as field-identification guidance.

Macroscopic characters

Agent source-checked

The 2012 treatment reports a pileus 7–15 mm across, adnexed lamellae and a stipe 40–65 × 1.5–2 mm, without an annulus. These are selected characters from that treatment; the original 1993 description has not been inspected here. [guzman-2012-thailand]

Microscopic characters

Agent source-checked

The 2013 holotype study reports spores 9.6–12.0 × 6.4–8.4 × 5.6–7.2 µm, hexagonal to subrhomboid in frontal view and ellipsoid to elongate in lateral view; pleurocystidia 14.5–22 × 4–6.5 µm; and an ixocutis. The 2012 treatment gives spores 10–13 × 6–8 µm and pleurocystidia 16–20 × 5–6.5 µm. These overlapping measurements remain source-specific; no pooled range or third spore dimension is inferred for the 2012 account. [ramirez-cruz-2013-types] [guzman-2012-thailand]

04Distribution and ecology

Disputed

Both treatments place the XAL holotype collection 2 km west of Ban Hua Thanon on Ko Samui, Thailand, on 8 August 1991. The 2013 study labels it J. Allen F; the 2012 treatment uses Allen s.n. The differing collector designations are retained without equating them to a verified accession number. This locality documents examined material and does not define the full range. [ramirez-cruz-2013-types] [guzman-2012-thailand]

Known range
Not yet researched
Habitats
Not yet researched
Substrates
Not yet researched
Ecological associations
Not yet researched
Seasonality
Not yet researched

Ecological context

Agent source-checked

The holotype study records scattered to gregarious growth in rice paddies. The 2012 treatment describes rich meadow soil, citing the original description. These are source-reported habitat observations, not a comprehensive ecological profile. [ramirez-cruz-2013-types] [guzman-2012-thailand]

Occurrence records

Occurrence map — awaiting verified records

No occurrence points loaded.

Recorded observations are not equivalent to true biological range. Absence of records does not demonstrate absence of a species.

Occurrence provenance & future map methods
Source
Not yet supplied
Licence / retrieval date
Awaiting licence / Not retrieved
Coordinate uncertainty
Not reviewed
Sensitive records
unreviewed

Future ingestion will review licensing, coordinate uncertainty and sensitive locations. Sampling, clustering and date filters will operate on separately loaded datasets; no coordinates are embedded in this page.

05Chemistry

Measurements belong to studies, specimens and methods. A single concentration cannot stand in for a species.

Published assays · Measurements retain their original methodological context.
Study / yearMaterialMethodRecord
No verified assay records entered. This does not establish that no published assays exist.
Fields retained in each future assay record

Study, publication year, specimen, material, sample size, provenance, analytical method, preparation, storage, psilocybin, psilocin, baeocystin, norbaeocystin, aeruginascin, units, qualifiers and methodological notes. No concentrations have been invented for this prototype.

Modern quantitative assays

Not yet researched

Modern analytical studies have not yet been systematically searched and checked for this account.

Evidence assessment

Not yet researched

Chemical literature has not yet been reviewed for this account. No assay values are extracted; this does not establish compound presence or absence.

Assessments depend on material, preparation, storage, sampling and analytical methods. Measurements are literature records, not predictions of effects.

How chemistry records are structured ↗

06Molecular evidence

Not yet researched

Species-specific molecular findings have not yet been checked for this account; no sequence or phylogenetic claim is extracted.

07History

Agent source-checked

The name was published in Mycotaxon 46:156 (1993), as cited by both revisions and GBIF. The 2013 study adds observations on pileus-trama arrangement and caulocystidia. The original paper remains unchecked here. [ramirez-cruz-2013-types] [guzman-2012-thailand] [gbif-5459370-2026]

A place for the historical record

This account records the nomenclatural history checked so far. Broader historical research remains pending; interpretations must stay connected to their documentary sources.

Reading the scientific record ↗

08Conservation

Not yet researched

This section has not yet been researched for this account.

Assessment status
Not yet researched
Assessment authority / year
Not verified / Not verified

Not researched by Psilocybia, not assessed by a conservation authority, and Least Concern are different states. None should be inferred from another.

09Images & specimens

No verified, licensed scientific images supplied

Space is reserved for field photographs, herbarium specimens, microscopy and historical plates, with source and licence metadata.

Photographs are not presented as sufficient for mushroom identification.

10References

  1. T. Niskanen; B. Dentinger; A.M. Ainsworth; I. Kytövuori; J.T. Kim; G.W. Griffith; K. Liimatainen (2026). Re-shaping the family-level classification of Agaricineae (Agaricales, Basidiomycota) using a phylogenomic approach. Studies in Mycology 113(1), 115–134. DOI: 10.3114/sim.2026.113.03 Source record ↗

    Source class: primary.

    Source verification history
    • metadata: verified · 2026-09-10 · Codex (agent) (agent). Verification source

      Bibliographic identity inspected; publication year is distinct from retrieval date.

    • content: verified · 2026-09-10 · Codex (agent) (agent). Verification source

      Family treatment Agrocybaceae, Table 1 and classification discussion inspected in the PDF. Effective online date in paper: 1 April 2026; Crossref issue date differs, so the record retains year only.

    • doi: verified · 2026-09-10 · Codex (agent) (agent). Verification source

      DOI and title matched against the cited bibliographic record; not just resolver availability.

  2. Virginia Ramírez-Cruz; Gaston Guzmán; Laura Guzmán-Dávalos (2013). Type studies of Psilocybe sensu lato (Strophariaceae, Agaricales). Sydowia 65(2), 277–319. Source record ↗

    Source class: primary.

    Source verification history
    • metadata: verified · 2026-09-10 · Codex (agent) (agent). Verification source

      Bibliographic identity checked against the publication.

    • content: verified · 2026-09-10 · Codex (agent) (agent). Verification source

      Full PDF inspected, with goniospora pp. 291–292 and ovoideocystidiata pp. 302–303 read in detail. No numeric microdimensions transcribed because extracted unit glyphs are unreliable. Qualitative cystidial observations and the type voucher are used.

  3. GBIF Secretariat (2026). Psilocybe samuiensis — GBIF Backbone Taxonomy record 5459370; accessed 14 September 2026. . Source record ↗

    Source class: taxonomic database.

    Source verification history
    • metadata: verified · 2026-09-14 · Codex (agent) (agent). Verification source

      Full API name record inspected: nomenclature, species rank, acceptance and older family placement. lastInterpreted is in 2023; retrieval is not a new taxonomic revision.

    • content: verified · 2026-09-14 · Codex (agent) (agent). Verification source

      Full API name record inspected: nomenclature, species rank, acceptance and older family placement. lastInterpreted is in 2023; retrieval is not a new taxonomic revision.

  4. Gastón Guzmán; Florencia Ramírez Guillén; Kevin D. Hyde; Samantha C. Karunarathna (2012). Psilocybe s.s. in Thailand: four new species and a review of previously recorded species. Mycotaxon 119, 65–81. DOI: 10.5248/119.65 Source record ↗

    Source class: primary.

    Source verification history
    • metadata: verified · 2026-09-14 · Codex (agent) (agent). Verification source

      Full PDF title page and Crossref title, authors, volume, pages and DOI matched. Selected samuiensis treatment on p. 69 inspected; measurements checked against page image. Original 1993 paper not inspected.

    • content: verified · 2026-09-14 · Codex (agent) (agent). Verification source

      Full PDF title page and Crossref title, authors, volume, pages and DOI matched. Selected samuiensis treatment on p. 69 inspected; measurements checked against page image. Original 1993 paper not inspected.

    • doi: verified · 2026-09-14 · Codex (agent) (agent). Verification source

      Full PDF title page and Crossref title, authors, volume, pages and DOI matched. Selected samuiensis treatment on p. 69 inspected; measurements checked against page image. Original 1993 paper not inspected.

Claim provenance

Source checks record what was inspected. Publication approval and section review are separate editorial decisions.

Name, authorship and original publication citation checked in the type revision and GBIF name record.

Fields: taxonomy.canonical_name, taxonomy.accepted_name, taxonomy.genus, taxonomy.specific_epithet, taxonomy.authority, taxonomy.publication_year

Species retained in the type revision and corroborated by GBIF acceptance; comprehensive synonymy review remains pending.

Fields: taxonomy.status

Follow the 2026 family treatment, which includes Psilocybe in Agrocybaceae.

Fields: taxonomy.family

GBIF retains Hymenogastraceae in a record interpreted in 2023.

Fields: taxonomy.family

  • gbif-5459370-2026 — family, lastInterpreted

    Source checked · Accessed 2026-09-14 · Codex (agent). Selected source passage inspected; no human scientific review. Quantitative type passages checked against PDF page images.

This scoped account compares two published treatments of the Thai holotype, covering selected morphology, habitat and collection provenance. Original-description coverage and the broader literature review remain incomplete.

Fields: overview.text

The 2012 treatment reports a pileus 7–15 mm across, adnexed lamellae and a stipe 40–65 × 1.5–2 mm, without an annulus. These are selected characters from that treatment; the original 1993 description has not been inspected here.

Fields: description.macroscopic.text

The 2013 holotype study reports spores 9.6–12.0 × 6.4–8.4 × 5.6–7.2 µm, hexagonal to subrhomboid in frontal view and ellipsoid to elongate in lateral view; pleurocystidia 14.5–22 × 4–6.5 µm; and an ixocutis. The 2012 treatment gives spores 10–13 × 6–8 µm and pleurocystidia 16–20 × 5–6.5 µm. These overlapping measurements remain source-specific; no pooled range or third spore dimension is inferred for the 2012 account.

Fields: description.microscopic.text

The holotype study records scattered to gregarious growth in rice paddies. The 2012 treatment describes rich meadow soil, citing the original description. These are source-reported habitat observations, not a comprehensive ecological profile.

Fields: ecology.narrative.text

Both treatments place the XAL holotype collection 2 km west of Ban Hua Thanon on Ko Samui, Thailand, on 8 August 1991. The 2013 study labels it J. Allen F; the 2012 treatment uses Allen s.n. The differing collector designations are retained without equating them to a verified accession number. This locality documents examined material and does not define the full range.

Fields: distribution.narrative.text

The name was published in Mycotaxon 46:156 (1993), as cited by both revisions and GBIF. The 2013 study adds observations on pileus-trama arrangement and caulocystidia. The original paper remains unchecked here.

Fields: history.text

The 2012 treatment lists Allen s.n. (holotype XAL).

Fields: distribution.narrative.text

The 2013 treatment lists J. Allen F (XAL, holotype).

Fields: distribution.narrative.text

Conflicting evidence

Resolved: taxonomy.family

The database retains an older family placement.

Adopt Niskanen et al. (2026) for family placement; use GBIF to corroborate nomenclature and acceptance. — Codex (agent), 2026-09-14

Unresolved: distribution.narrative.text

The two treatments report the same locality, date and holotype herbarium but different collector designations. The specimen label has not been independently inspected.