Psilocybe stuntzii

Psilocybe stuntzii is a small, fragile, blue-bruising mushroom of the Pacific Northwest. Its hygrophanous cap is conic to convex (1.5-5 cm), dark chestnut to olive-brown, fading to tan or pale yellow as it dries, and is covered by a thin separable gelatinous pellicle. A distinguishing feature is the persistent membranous annulus (ring) on its slender stem, which often bruises bluish. The spore print is dark purple-brown. It contains the psychoactive compounds psilocybin and psilocin, though at low potency relative to other bluing Psilocybe species.

History

Psilocybe stuntzii is a recently described species, not an ancient ceremonial mushroom. In the fall of 1972, large numbers of a strongly blue-bruising, ringed mushroom appeared on bark mulch spread across the University of Washington campus in Seattle. It was formally named Psilocybe stuntzii by mycologists Gastón Guzmán and Jonathan Ott in 1976, honoring Dr. Daniel Stuntz, who made the type collections. Within a few years it became one of the most commonly used wild psilocybin mushrooms in the Pacific Northwest, spreading readily through landscaping wood chips and newly laid lawns.

Overview

Psilocybe stuntzii fruits gregariously to cespitose from late summer into early winter on conifer wood chips, bark mulch, soils rich in woody debris, and new lawns, alongside Psilocybe semilanceata in pastures. It is abundant in Oregon, Washington and British Columbia. Its great danger lies in its strong resemblance to the deadly Galerina autumnalis, an amatoxin-containing mushroom that shares the same habitat and has been found growing intertwined with it; fatal poisonings have resulted from confusing the two. The key, life-saving distinction is the spore print: purple-brown in P. stuntzii versus rusty brown in Galerina. Reported chemical analyses (Beug & Bigwood; Repke et al.) found up to roughly 0.36% psilocybin, 0.12% psilocin and 0.02% baeocystin on a dry-weight basis.