Mescaline molecule. Computer graphic of the drug mescaline (formula C11.H17.N.O3). The atoms (spheres) are colour-coded: carbon (yellow), oxygen (red), nitrogen (blue) & hydrogen (white). Mescaline is an illegal hallucinogenic drug, which is produced from the dried tops (buttons) of the peyote cactus. The cactus grows wild in Texas and Mexico, and was extensively used by the native Americans. The drug produces a feeling of euphoria and an altered perception of time, space and colour. The Aztecs also valued the buttons, making use of then in religious ceremonies.