Mescaline. Coloured scanning electron micrograph (SEM) of crystals of mescaline. Mescaline is an illegal hallucinogenic drug produced from the dried tops, or buttons, of the peyote cactus (Lophophora williamsii). This cactus is found growing wild in Texas and Mexico and was used extensively by both Native Americans and Aztecs in religious ceremonies. It is usually taken by chewing the buttons or making them into an infusion. Mescaline produces feelings of euphoria and an altered perception of time, space and colour.