Psilocybe cyanescens

Identification, in outline

Psilocybe cyanescens takes its common name from the wavy, undulating margin of its caramel-brown, hygrophanous cap. It grows in dense clusters and bruises an intense blue-green where handled. The catch is severe: deadly Galerina marginata fruits on the same wood, in the same season, and can look confusingly similar — misidentification here can be fatal.

A mushroom of the human-made world

What makes P. cyanescens interesting culturally is its habitat: not ancient forest or sacred meadow, but woodchip and bark mulch. As municipal landscaping spread lignin-rich mulch through parks, verges, and gardens, the species spread with it, colonising a niche humans unintentionally created. It is a genuinely modern, urban mushroom.

Active compounds

The wood-loving psilocybes are among the most potent in the genus, rich in psilocybin and psilocin, with concentrations that swing widely between flushes — a large part of why wild material is so unpredictable.

Toxicity, legality, and safety

Beyond the deadly Galerina lookalike, the hazards are the familiar ones: high, variable potency; prohibition in most jurisdictions; and the reported phenomenon of temporary “wood-lover paralysis.” This page documents the species, not its use.

Conservation

Spreading rather than declining — its mulch habitat expands with every landscaped park — and of no conservation concern.