About Conocybe filaris (Fr.) Kühner
The cap of Conocybe filaris (also called Conocybe rugosa) starts out conical and expands to become flat, usually with a central umbo. The cap is less than 3 cm across, with a smooth brown surface, and its margin is often striate. The gills are rusty brown, closely spaced, and adnexed. The stalk is 2 mm thick and 1 to 6 cm long, with a smooth brown surface, and it bears a prominent, movable ring. Spores of this species are rusty brown, and species identification is often difficult without the use of a microscope. This species grows in woodchips, flowerbeds, and compost piles. It has been recorded in Europe, Asia, and North America, and it is especially common in the Pacific Northwest. This species is deadly poisonous. Its fruiting bodies contain alpha-amanitin, a cyclic peptide that is highly toxic to the liver; this toxin is responsible for many poisoning deaths caused by mushrooms from the genera Amanita and Lepiota. Mushrooms of this species are sometimes mistaken for species in the genus Psilocybe.
