Psilocybe baeocystis

Singer & A.H. Sm. · Psilocybe sect. Cyanescens

Knobby top · Bottle cap · Blue bell

High potency

A potent Pacific Northwest species, and the mushroom baeocystin was named after. Its dark olive-brown, often distorted cap makes it one of the more distinctive members of the group.

Photo: Alan Rockefeller, CC BY, source.

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1 deadly look-alike. Galerina marginata can be mistaken for this species and causes irreversible organ damage. How to tell them apart.

Potency

Psilocybin: 0.15–0.85% of dry weight
Psilocin: 0.06–0.59% of dry weight
Total tryptamines: 0.3–1.55%
Relative to cubensis: 1.59×

Notably high baeocystin content alongside psilocybin and psilocin. Roughly one and a half times cubensis.

Dose ranges for this species

Tier	Dried	Psilocybin-equivalent	What to expect
Threshold	0.19–0.32 g	1.9–3.2 mg	Mild body load, slight colour and texture enhancement, mood shift.
Light	0.32–0.63 g	3.2–6.3 mg	Clear perceptual change. Surfaces breathe, emotions amplify, time distorts mildly.
Common	0.63–1.58 g	6.3–15.8 mg	Full psychedelic effect. Strong visuals with eyes closed, altered thought, emotional intensity.
Strong	1.58–3.15 g	15.8–31.5 mg	Ordinary self-reference goes. Marked visual distortion, time stops behaving.
Heavy	3.15 g and above	31.5 mg and above	Complete disruption of the ordinary sense of being a person in a place.

Scaled from the standard dried-cubensis tables by this species’ representative alkaloid content. Because that content varies between flushes, treat every figure as an estimate and start below it. Open the full calculator.

Identification

Easiest way to tell: A dark olive, knobbly, often distorted cap with a separable gelatinous skin, on a ringless stem in Pacific Northwest mulch.

Cap: 1.5–5 cm, conical to convex, often irregular or knobbly, dark olive to buff-brown, with a gelatinous separable pellicle and a translucent striate margin.
Gills: Adnate, greyish becoming dark purple-brown.
Stem: 5–8 cm, whitish to pale, sometimes tinged blue at the base.
Ring: Absent.
Flesh: Bruises blue.
Spore print: Dark purple-brown
Bruising: Blue

Habitat

Substrate: Wood chips, Bark mulch, Conifer debris, Lawns rich in woody matter
Regions: Pacific Northwest of the United States, British Columbia
Season: August to December

Common on landscaped ground and in conifer debris.

Look-alikes

Compare every mushroom look-alike of Psilocybe baeocystis side by side, or read the full look-alikes guide.

Galerina marginataDeadly
Spore print: Rusty brown to ochre-brown

Cultivation

advanced

Rarely cultivated. Outdoor beds are possible but it is much less tractable than cyanescens.

Cultivation guides

Medication interactions

These interactions come from psilocin itself, so they apply to every species; a more potent species means a larger dose of it. These medications are graded dangerous, caution, increases or not studied on Fungodex. Not listed here does not mean safe; check the full checker covers 24.

Sources

[1]Stamets, Psilocybin Mushrooms of the World (1996)
[2]Beug & Bigwood, 'Psilocybin and psilocin levels in twenty species' (1982)

How we research this: sources, evidence grading, review and updates.