“Strain” has no formal rank in fungal naming. In research it usually labels one culture or sample. A 2021 genome paper sequenced material it called “strain P.envy” and stated plainly that “the strain name is anecdotal” (McKernan et al., 2021). A news report on a US potency contest notes that people often say “strain” where “cultivar” is the technical term (Inverse, 2021).
A strain name is not a chemical specification. A 2026 study grew 14 named Psilocybe cubensis strains under identical conditions and found total tryptamines varied more than 7.8-fold between them, with psilocybin also varying between single mushrooms of one strain; the authors concluded that strain identity alone cannot predict content (Sharchaton et al., 2026).
Ancestry is uncertain too. A 2023 genome study found cultivated lines fell into five broad groups and said their pedigrees “exist in lore but are not authenticated” (McTaggart et al., 2023). When a source uses “strain”, the useful questions are what material it means and how it was identified.
Sources
- McKernan et al., 2021, F1000Research data note
- Sharchaton et al., 2026, Journal of Fungi
- McTaggart et al., 2023, Current Biology
- Inverse, 2021
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