Panaeolus bisporus

Panaeolus bisporus, also known as Copelandia bisporus is a rare and widely distributed little brown mushroom that bruises blue and contains the psychedelic compound psilocybin.

This mushroom is similar macroscopically to Panaeolus tropicalis, Panaeolus cambodginiensis and Panaeolus cyanescens, but can be differentiated using a microscope by its two spored basidia.

Description
This is a little brown mushroom that grows on dung and has black spores. It has been found in Hawaii, Southern California, North Africa, Spain and Switzerland.

The cap is 15-30 mm tan to gray fading to black sometimes when covered with spores and with a defined ring zone somewhat globe shaped or bell shaped to convex, hardly expanding, margin often torn and pedaled, smooth not viscid, and slightly wrinkled and pitted with age. Dark grey-brown drying whitish. The gills are adnexed or narrowly attachedtightly packed, mottled gray to jet black, white edges. The stem is white, fibrous, 65-120 mm long 2-3 mm thick, hollow, translucent gray, bruising heavily blue where bruised. It produces spores that are jet black, elliptical, 12-14 x 8-10 x 6-7.5 μm smooth and opaque, elongated with germ pore straight off the end. Microscopic features are 2 spored basidia 18 - 23 × 8-10 μm, cheilocystidia are bottle shaped and clear 20-30 μm, metuloids with yellow brown walls 40-55 × 12-15 μm some with excreted crystals.

Its habitat are saprotrophic on grasses.