Psilocybe semiinconspicua

Psilocybe semiinconspicua

Psilocybe semiinconspicua
Scientific classification
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Strophariaceae
Genus: Psilocybe
Species: P. semiinconspicua
Binomial name
Psilocybe semiinconspicua
Guzmán & J. M. Trappe

Psilocybe semiinconspicua is a psilocybin mushroom in section Semilanceatae native to the state of Washington in the United States. The mushroom is small, rare, difficult to see and stains blue where damaged. It can be mistaken for Psilocybe silvatica and can be distinguished by its more conic cap, narrower spores and narrower cheilocystidia.

This mushroom is only known from the type locality where it was found at the Glacier Peak Wilderness Area in Wentachee National Forest, Washington, USA.



The cap is 7–12 mm and convex, becoming nearly plane in age. It is hygrophanous, has a smooth surface, and is olive black when moist, fading to brownish orange or dark reddish brown as it dries.


The gills are Adnate light grayish brown at first, turning dark purple as the spores mature.


Psilocybe semiinconspicua spores are 8–10 x 5–7 µm, subovoid to ellipsoid, thick-walled, and yellowish brown to dark purple brown in deposit.


The stipe is 15–20 x 2 mm, hollow, has an equal width, and is white with whitish or brownish floccose scales, drying to a reddish brown. It stains blue near the base.

Microscopic features

The Psilocybe semiinconspicua basidia have four spores each. The cheilocystidia are sublageniform and 24–30 x 6–8 µm. No pleurocystidia have been observed. Clamp connections are present.


Psilocybe semiinconspicua is gregarious in small groups among shrubs on a creek bank.


  • Guzman and Trappe 2005: The Hallucinogenic and Nonhallucinogenic Species of the Genus Psilocybe Fayod (Basidiomycotina) in Washington State, USA: New Records and a New Species - International Journal of Medicinal Mushrooms 583-590