The genus Psilocybe contains roughly 180 small to medium-sized saprophytic mushroom species that can be found in a wide range of habitats: dungs, mosses, soils, grasslands, or decaying wood debris. When moist, most species have viscid, deep-brown caps that fade in drying to yellowish brown (i.e., are hygrophanous). The more active species, particularly those high in psilocin, bruise bluish where injured. The gills are usually dark brown in color with whitish edges, and range from being subdecurrent to acutely ascending in their attachments.



Almost any little brown mushroom can be mistaken carelessly for a Psilocybe - with potentially disastrous results! A good spore print is crucial, as it will eliminate the brown spored genera (Galerina, Inocybe, Conocybe etc.), which contain many poisonous species. Among the dark-spored genera, Coprinus has deliquescing gills, Psathyrella typically has a non-viscid cap and bruises stains blue, Panaeolus species with a viscid cap grow on dung and have black spores, and Hypholoma (= Naematoloma) and Stropharia species are usually brightly coloured, while the cap color in Psilocybe (with the notable exception of Psilocybe cubensis) is typically some shade of brown, gray, or buff.