The medicinal plants of the Guajá people of eastern Amazonia include a number of plants that are used to repel the ghosts of the dead. This work discusses the aiyã ghost repellent plants in terms of their symbolic meaning, biological efficacy, and historical ecological context. Ghost repellent plants are identified through their pungent smell, which counteract the disease-causing foul smell of the ghosts of the dead. The efficacy of the cure may also relate to its interference with the so-called "Proustian phenomenon," which refers to the power of olfactory stimuli to evoke memories of the past. As such, ghost repellent plants may function, in a sense, to repel memory and cope with grief. Finally, evidence is discussed the predominance of ghost repellent plants among the Guajá is an artifact of massive depopulation in the wake of European contact.
Guajá; Medicinal Plants; Ecology; Olfaction; Grief