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.
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.
