Which substance is derived from a specific cactus and contains mescaline?

The substance that is derived from a specific cactus and contains mescaline is Peyote. Peyote is a small, spineless cactus (Lophophora williamsii) native to Mexico and the southwestern United States. This cactus has been used for thousands of years by Indigenous peoples for its psychoactive properties, primarily due to the presence of mescaline, a hallucinogenic compound.

Psychoactive substances derived from other sources do not contain mescaline. For instance, shrooms refer to certain mushrooms containing psilocybin, which is quite different from mescaline. Ketamine is a synthetic anesthetic with dissociative properties, and DXM (dextromethorphan) is an over-the-counter cough suppressant that can produce dissociative effects at high doses. However, neither of these substances is derived from cactus or contains mescaline.