Loco (Loko) is the lwa of vegetation, of trees and of healing herbs in Haitian Vodou, the guardian of the temple and the patron of the priesthood. As the spirit of the sacred tree, he is understood as a kind of axis linking the community and its sanctuary to the world of the spirits, the great tree being, in Vodou as in the West African traditions from which it descends, a natural conduit between earth and the divine, its roots in the ground of the ancestors and its branches in the sky. Because he presides over the healing power of plants and herbs, Loco is closely associated with the knowledge of remedies and with the work of healing that is an important part of Vodou practice. His special role, however, is his connection with the priesthood and with initiation.
Loco, with his wife Ayizan, herself regarded as the first and archetypal priestess, is honoured as a founder and guardian of the office of the Vodou priest, and it is Loco who is associated with the conferring of the asson, the sacred beaded rattle and bell that is the emblem and instrument of the initiated priest or priestess (the houngan or manbo) and the sign of their authority to serve the spirits. To receive the asson is to be recognised as a full priest, and Loco stands behind that recognition as the patron of the priestly line.
In the correspondences with the Catholic saints he is variously associated, and he is honoured within the Rada rite among the older, benevolent spirits. Vodou is a living religion with an ordered priesthood and deep traditions of herbal healing, and Loco is the guardian of both, the spirit of the sacred tree, of the medicines drawn from the green world, and of the priesthood that serves the community and its lwa.