The mushroom Psilocybe semilanceata, which contains hallucinogenic indole alkaloids, has been used as a narcotic drug in Norway. Its psilocybin content, habitats, and distribution across the country were investigated. The mushroom grows on grassy sites throughout most of Norway from mid-August to mid-October. Psilocybin content in dried mushrooms varied considerably, from 0.17 to 1.96%. Smaller mushrooms had the highest percentage concentration, while larger mushrooms had the highest total amount in milligrams. The psilocybin content makes P. semilanceata a potent hallucinogenic drug.
A screening of Norwegian mushrooms for hallucinogenic indole alkaloids used HPLC with ultraviolet, fluorescence, and electrochemical detection. Psilocybin and psilocin were found in two species: Pluteus salicinus and Conocybe cyanopus. Dried Pluteus salicinus contained 0.35% psilocybin and 0.011% psilocin; dried Conocybe cyanopus contained 0.33-0.55% psilocybin and 0.004-0.007% psilocin.