Coca is the least intoxicating plant this atlas describes and one of the most religiously important, which makes it a useful corrective to the assumption that sacredness follows potency.
The leaf is chewed with a mineral alkali to release its alkaloids, and the effect is mild, comparable to strong tea: alertness, tolerance of altitude, cold and hunger, and a slight numbing of the mouth. Nobody has visions.
Its ritual centre is the k'intu, a small fan of three perfect unbroken leaves, held in both hands, breathed on, and offered. It is given to the apus, the mountain lords, to Pachamama, the earth, and to the dead, and it is also given between people. Catherine Allen's fieldwork in the Peruvian community of Sonqo shows the same gesture running through both directions: the exchange of coca between two people and the offering of coca to a mountain are the same act, and both are instances of the reciprocity that organises Andean social and religious life. To decline coca is to decline a relationship.
Leaves are also cast and read for divination, and coca appears in every serious occasion: healing, planting, building, travel, burial, and the settling of disputes.
Archaeologically it is old. Coca leaves and the lime containers used with them appear in Andean and coastal burials over thousands of years, and it was under Inca administration a regulated and high status crop.