Mescaline or 3,4,5-trimethoxyphenethylamine is a naturally-occurring psychedelic alkaloid of the phenethylamine class used mainly as an entheogen. It occurs naturally in the peyote cactus (Lophophora williamsii), the San Pedro cactus (Echinopsis pachanoi) and the Peruvian Torch cactus (Echinopsis peruviana), and in a number of other members of the Cactaceae plant family. It is also found in small amounts in certain members of the Fabaceae (bean) family, including Acacia berlandieri.