Psilocybe cyanescens, also known as wavy caps is a potent psychedelic mushroom whose main active compounds are psilocybin and psilocin. It belongs to the family Strophariaceae and was described from Kew Gardens, England, by E. M. Wakefield in the 1940s. This species is closely related to Psilocybe azurescens which can be distinguished by its conical and acutely umbonate pileus, larger fruit bodies and longer spores.