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Psilocybe caerulescens var. caerulescens Murrill

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Scientific name
Psilocybe caerulescens var. caerulescens
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Preliminary Category
Proposed by
Ricardo Garcia-Sandoval
Ricardo Garcia-Sandoval
Roberto Garibay Orijel
Roberto Garibay Orijel
Comments etc.
Anders Dahlberg

Assessment Notes

After a local level assessment, this species was considered to be included as threatened in the Mexican law. Considering its cultural relevance for several cultural groups in Mesoamerica, its assessment at global level its necessary, in order to provide a complement and a general referential frame.
This species was described in the USA by Murrill in 1923, and since then it has been collected constantly in at least seven countries in America. The species is saprophytic, and grows in soil, in open areas, with some level of disturbance. The species is known from different vegetation types, ranging from mountain cloud forest to grassland.
This species represents a particular interest because it consumed as part of cultural rites by several cultural groups in Mesoamerical region. Also the species is consumed as a recreational activity by the general public. The species is popular as a recreational resource, and several protocols for its cultivation are available. Considering this, its consumption, either ritual or recreational, may not represent a threat for the natural populations.


The species is a saprophytic generalist, able to grow in open and disturbed areas, and it is known at least from seven countries in America. Its use, either bio-cultural or recreational, do nor represents a real threat for the natural population as along as it is very reduced, and recreational uses also is supplied by private cultivation.

Taxonomic notes

Psilocybe caerulescens Murrill, Mycologia 15(1): 20 (1923)
= Psilocybe caerulescens var. mazatecorum R. Heim 1957
= Psilocybe caerulescens var. albida R. Heim 1973
= Psilocybe caerulescens var. nigripes R. Heim 1957
= Psilocybe bispora Guzmán, Franco-Mol. & Ram.-Guill. 2007
= Psilocybe caribaea Guzmán, T.J. Baroni & Tapia 2003
= Psilocybe villarrealiae Guzmán 1998
= Psilocybe weilii Guzmán, Stamets & F. Tapia 1997

Species with pileus 20-88 mm diameter, campanulate to convex, slightly umbilicate; deep olive at first, then becoming pale colored, darker umbo, hygrophanous; veil usually fugacious on pileous. Lamellae light avellaneous gray to sepia, sinuate-adnate to bluntly adnate, close to subclose, broad. Stipe 40-122 x 2-10 mm, equal, hollow, glassy white; basal mycelium white, occasionally with white rhizomorphs.
Gregarious to cespitose, rarely solitary, on soil, mostly in shady places or rich earth recently moved or altered, fruiting in summer.
Descriptions in Murrill 1923, Guzman 1983, Singer & Smith 1958.

This species was described from Alabama, USA, from a locality with “...rich soil mixed with humus on the shaded bank of a small stream”, no additional information was provided regarding the vegetation type, but Guzman et al. (1988) mention the vegetation at type locality as “..equivalent to Mexican mountain cloud forest”.

Guzman et al. (1988) mention this species as the one used by Mazateco people in their rituals, and the same described by Heim as Psilocybe mazatecorum ( = Psilocybe caerulescens var. mazatecorum R. Heim 1957). In 1988 Guzman et al. the species is recorded from Guadalajara in Pinus-Quercus forest.

Al least four varieties has been described in P. caerulescens, besides the typical one, but all have been synonymized (Guzman 1995, 2005). Also several species were synonymized after comparison of the ITS region sequenced from type specimens (Ramirez-Cruz 2013).

This species has a quite variable morphology, and several varieties and species has been erroneously described (Ramirez-Cruz 2013). Additional research is needed for a better understanding of the variability in the species.

Why suggested for a Global Red List Assessment?

Psilocybe caerulescens is considered as threatened in Mexican law. The species represents and important bio-cultural resource, because it is consumed on rituals, by several cultural groups in Mesoamerica. In Mexico the species distributes in mountain cloud forest, grassland, and Pinus or Pinus-Quercus forest.
Considering its low specificity in vegetation type or habitat, its wide range distribution, and the fact that can be cultivated, its population is assumed be very numerous and non threatened. In consequence it should be listed as less concern.

Geographic range

This species was described from Alabama, USA, but additional specimens have been collected in Mexico (Oaxaca, Veracruz, Jalisco, CDMX, Puebla), Ecuador (Napo), Costa Rica (Santo Domingo), Venezuela (Sucre), Panama (Veraguas), and Brazil (Parana). The provided maps include data form Mycoportal and GBIF.

Population and Trends

This species has been recorded constantly since first discovered in 1923, 89 records were recovered from GBIF, corresponding with four countries, and 100 specimens are registered in the Mycoportal, additional 189 observations with research grade, between 2007 and 2017, were recovered from iNaturalist and Mushroom Observer.
Considering the low specificity in vegetation type or habitat for this species, and its wide range distribution, its populations may be very numerous.

Population Trend: Stable

Habitat and Ecology

This species has been collected in several vegetation types, including mountain cloud forest, grassland, Pinus-Quercus forest, and river banks. This species grows in soil, usually in open areas, and is considered to be saprophytic.
This species is cultivated at low scale, mostly for private use. Psilocybe caerulesces do not has a restricted vegetation type, and is able to grow in open areas with some level of disturbance.

Temperate ForestSubtropical/Tropical Dry ForestSubtropical/Tropical Moist Montane ForestTemperate ShrublandTemperate Grassland


There are no significant threats identified for this species, considering the species is a saprophytic generalist, not restricted to a particular vegetation type, and able to grow in open areas with some level of disturbance. Also, even when the species is consumed with ritual and recreation purposes, because the species can be cultivated, its recreation use do not imply a threat.

Intentional use (species being assessed is the target)

Conservation Actions

There are not specific conservation actions for this species, as long as there are no particular threats, beyond a non specific loss of habitat.

Resource & habitat protection

Research needed

Research is needed in phylogenetics and taxonomy of the species. This species exhibits a large morphological variability, and it is distributed across a wide range of vegetation types and areas, this may be indicative of a potential species complex.


Use and Trade

This species is consumed as part of traditional cultural rituals by several ethnic groups in Mesoamerica, but its ritual consumption do not represents a threat. The species also is consumed for recreational purposes, but considering that its trade is restricted by the law in several countries, and the species can be cultivated, this recreational use do not represent a threat.

Other (free text)


Guzmán, G. (2005). Species Diversity of the Genus Psilocybe (Basidio- mycotina, Agaricales, Strophariaceae) in the World Mycobiota, with Special Attention to Hallucinogenic Properties. International Journal of Medicinal Mushrooms, 7, 305-331.
Guzmán, G., Jacobs, J. Q., Ramírez-Guillén, F., Murrieta, D. y Gándara, E. (2005). The Taxonomy of Psilocybe fagicola-complex. The Journal of Microbiology, 43(2), 158-165
Guzmán, G. (1983). The genus Psilocybe. Nova Hedwigia 74, Cramer.
Guzmán, G. (1995). Supplement to the monograph of the genus Psilocybe. Taxonomic Monographs of Agaricales. Bibliotheca Mycologica 159, 91-141.
Guzmán, G., Horak, E., Halling, R., Ramírez-Guillén, F. (2009). Further studies on Psilocybe from thr Caribbean, Central America and South America, with descriptions of new species and remarks to new records. Sidowia 61, 215-242.
Ponce-Reyes, R., Nicholson, E., Baxter, P. W. J., Fuller, R. A. and Possingham, H. (2012). Extinction risk in cloud forest fragments under climate change and habitat loss. Diversity and Distributions 19, 518–529.
Ramírez-Cruz, V. (2010). Taxonomía y análisis filogenético del género Psilocybe sensu lato (Fungi, Agaricales). Tesis de Doctorado en Ciencias en Biosistemática, Ecología y Manejo de Recursos Naturales y Agrícolas. Universidad de Guadalajara, México.
Ramírez-Cruz,V.,  Guzmán, G., Villalobos-Arámbula, A.R., Rodríguez, A., Matheny, P.B., Sánchez-García, M. and Guzmán-Dávalos, L. (2013). Phylogenetic inference and trait evolution of the psychedelic mushroom genus Psilocybe sensu lato (Agaricales). Botany 91, 573–591.

Country occurrence

Regional Population and Trends

Country Trend Redlisted