Psilocybe is a genus of mushroom-forming fungi and the source of the word psilocybin. Index Fungorum lists it as Psilocybe (Fr.) P. Kumm., 1871, marked as a conserved name with a conserved type (Index Fungorum). Paul Kummer raised it to a genus, building on a group Elias Fries had named.
DNA showed the old genus was two lineages. In 2007 six mycologists, led by Scott Redhead of Agriculture and Agri-Food Canada in Ottawa, proposed keeping the name for the bluing species with Psilocybe semilanceata as its type; the fungal nomenclature committee backed it 13 to 0 (Norvell, 2009; Norvell et al., 2010). The non-bluing species went to Deconica.
How big is it? A 2022 study put Psilocybe in the strict sense at about 165 species, with psilocybin measured in only about 45 (Bradshaw et al., 2022). GBIF, which still mixes in unmoved Deconica names, listed 324 accepted species on 25 October 2026 (GBIF). The family is unsettled too: GBIF files it in Hymenogastraceae (GBIF), while a 2026 study proposes a new family, Agrocybaceae (Niskanen et al., 2026).
Sources
- Index Fungorum web service: Psilocybe
- Norvell, 2009, Mycotaxon 110: Report of the Nomenclature Committee for Fungi 15
- Bradshaw et al., 2022, Applied and Environmental Microbiology
- Niskanen et al., 2026, phylogenomic family classification (PMC)
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