species

Panaeolus

Dung-loving "mottlegills" with jet-black spores. A potent minority produces psilocybin — a textbook case of the chemistry recurring in nutrient-rich, contested substrates.

MMI Editorial June 23, 2026

Genus at a glance

FieldDetail
ClassificationGenus
FamilyBolbitiaceae (formerly Coprinaceae)
Described species~120 (a minority psychoactive)
Spore printJet black to purple-black
DistributionCosmopolitan; richest in tropical & temperate grassland
HabitatDung of large herbivores, manured and grassy soil
Key alkaloidsPsilocybin, psilocin; some species also serotonin/urea derivatives

Overview

Panaeolus ("mottlegills") are small, slender, dung-loving mushrooms with mottled grey-black gills and a jet-black spore print. Most are harmless decomposers of manure and rich soil; only a minority produce psilocybin, but those that do can rival potent Psilocybe. The coprophilous (dung-dwelling) habit is ecologically telling — dung is a nutrient-rich, fiercely contested substrate, and psilocybin production appears repeatedly in fungi that colonise it, supporting the hypothesis that the compound deters fungus-eating insects.

The genus sits taxonomically apart from Psilocybe — closer to the inky-cap lineage — so its psilocybin is, again, convergent. The clearest separation from Psilocybe in the field is the spore print: jet black rather than purple-brown.

Documented species

SpeciesNotesDistribution
P. cyanescens (Copelandia)Highly potent; "blue meanies"; strong bluingPantropical
P. cinctulus (P. subbalteatus)Common, mildly active, weedy in compostTemperate worldwide
P. tropicalisPotent tropical speciesTropics
P. bisporusTwo-spored, active, weedyCosmopolitan (introduced)
P. africanusAfrican dung species, reported activeCentral Africa

Under-documented & emerging

The line between active and inactive Panaeolus is blurry and under-studied. Many species have never had alkaloid assays, and the genus is taxonomically unstable — the segregate genus Copelandia has been merged into and split from Panaeolus repeatedly. Tropical dung communities in Africa, South America, and Southeast Asia almost certainly contain undescribed psychoactive species, since collecting effort there is low and dung fungi fruit briefly and unpredictably. Even potency within a documented species varies widely with the host animal's diet and the substrate.

How to read this

Educational profile only — non-psychoactive and psychoactive Panaeolus grow side by side in the same pasture, so the genus is a textbook case of why field identification is difficult and risky.