Its flowers grow in small, pale yellow to white spherical clusters resembling Acacia (e.g. wattle) inflorescences.

The oldest clear evidence of use comes from pipes made of puma bone (Puma concolor) found with Anadenanthera beans presumably of the sister species A. colubrina, at Inca Cueva, a site in the Humahuaca gorge at the edge of the Puna of Jujuy Province, Argentina.

[15] Snuff trays and tubes similar to those commonly used for yopo were found in the central Peruvian coast dating back to 1200 BC, suggesting that insufflation of Anadenanthera beans is a more recent method of use.

[17] Some indigenous peoples of the Orinoco basin in Colombia, Venezuela and possibly in the southern part of the Brazilian Amazon make use of yopo snuff for spiritual healing.

Yopo snuff was also widely used in ceremonial contexts in the Caribbean area, including Puerto Rico and La Española, up to the Spanish Conquest.

In some areas the unprocessed ground beans are snuffed or smoked producing a much weaker effect with stronger physical symptoms.

Some tribes use yopo along with Banisteriopsis caapi to increase and prolong the visionary effects, creating an experience similar to that of ayahuasca.

The first report of the effects of hallucinogenic snuff prepared from the beans of Anadenanthera peregrina dates back to 1496 when it was observed by Friar Ramon Pane, who was commissioned by Christopher Columbus, among the Taino Indians of Hispaniola.

The description of its effects reads in part: "This kohobba powder," described as "an intoxicating herb, is so strong that those who take it lose consciousness; when the stupefying action begins to wane, the arms and legs become loose and the head droops."

The administering witch-doctor took the drug along with his patients, intoxicating "them so that they do not know what they do and ... speak of many things incoherently", believing that they are in communication with spirits.

[20] When taken orally by some tribes in South America, small amounts are often combined with alcoholic chichas (maize beer).

The beans were a main ingredient in bilca tauri, an oral purge medicine used to induce ritual vomiting once a month.

Some South American tribes have been documented to use various bean preparations along with Banisteriopsis caapi, an herb containing monoamine oxidase inhibitors (MAOIs).