The plant has no confirmed wild population, sets seed poorly and is propagated from cuttings, which points to long cultivation, as with kava and Brugmansia. But there is no colonial record of it, unlike the mushrooms and ololiuqui which the friars documented extensively, and no archaeological evidence. So the plant looks ancient and the documentation begins in the twentieth century.
What would resolve this Discovery of a wild population would settle the origin. A colonial or pre-conquest reference, possibly under a name not yet connected to it, would settle the antiquity. Genetic work on cultivated clones could estimate how long it has been propagated vegetatively.
OpenEthnobotany, plant genetics, Mesoamerican ethnohistoryLeander J. Valdes III, Jose Luis Diaz and Ara G. Paul, Ethnopharmacology of Ska Maria Pastora (Salvia divinorum, Epling and Jativa-M.)