 "Psychotria viridis" is frequently used as a source of dimethyltryptamine in the preparation of ayahuasca, a psychoactive decoction.The bark of the species "Breonadia salicina" have been used in traditional African medicine for many years.The leaves of the Kratom plant ("Mitragyna speciosa") contain a variety of alkaloids, including several psychoactive alkaloids and is traditionally prepared and consumed in Southeast Asia, where it has been known to exhibit both painkilling and stimulant qualities, behaving as a μ-opioid receptor agonist, and often being used in traditional Thai medicine in a similar way to and often as a replacement for opioid painkillers like morphine.