[Ritual use of Anadenanthera seeds among South America natives].

Introduction: Several South-American native societies snuff psychoactive seeds in magic-religious rituals since ancient times.

Objectives: To describe archeological, historical and ethnographical evidences regarding the ritual use of vilca or yopo (Anadenanthera sp).

Development: Anadenanthera seeds were used in South America 3,000 years ago. Archeological studies found vilca seeds in funerary tombs from 1,000 BC in the north of Chile and Argentina; ceramics and snuff tubes were found in San Pedro de Atacama archeological sites from the same data, and in Tiwanaku ceremonial center in Bolivian Altiplano. Today, Anadenanthera sp is used by several native groups in Orinoco basin, where is known as yopo, and in the Brazilian and Colombian Amazon. Hallucinogenic effect is due to the presence of methyl-tryptamine derivatives. Most snuff is prepared from the roasted and powdered seeds, vegetable ash and/or lime obtained from shells.

Conclusions: Archeological and ethnographical data suggest that vilca was used and is still used by native shamans as a sacred seed in South America, due to its hallucinogenic effects.