Ancient medicinal plants of South America

Many archaeologists suggest that shamanic practices are ancient, starting at least 30,000 y ago (1⇓–3). As an analytical concept, anthropologists define shamans as religious practitioners who interact directly with the spirit world to help their people. Shamans in each culture have their own practices and are called by different names (e.g., chayanyi , curanderos , or vegetalistas ). Shamanic practices are found in indigenous groups all over the globe, from Australia to the Arctic. The core of these practices is altered states of consciousness (ASC), during which the shaman is able to perceive and interact with the spirit world. However, the rituals used to initiate ASC greatly vary, from Australians walking into their Dreamtime to Siberian shamans drumming into trance states (4). There are many purposes for these states, but ultimately, they are the gateway to spirits and deities who help cure the sick, bring rain, find lost objects, or otherwise help people medically, physically, emotionally, and/or spiritually (4, 5). Human neurology and physiology enable people to enter trance states, which can range in intensity and duration from a sort of daydreaming-like state to having powerful hallucinations while catatonic (6). Hallucinations can be initiated using various methods, including fasting, chanting, drumming, sensory deprivation, extreme pain, and consuming psychoactive plants. Often, shamans combine these various methods and will sometimes use psychoactive plants when they are available. These psychoactive agents can be consumed in a variety of ways, including simply eating them [e.g., the Huichols of west Mexico eat fresh and dried peyote buttons (7)], inhaling them as snuff [e.g., the Yanomamo of Venezuela inhale yakoana powder (8)], using enemas [e.g., the Maya used ritual enemas laced with various psychoactive plants (9)], and brewing them (8). South American shamans brew a tea called ayahuasca, which is the focus of … [↵][1]1Email: vanpoolc{at}missouri.edu. [1]: #xref-corresp-1-1