Among the indigenous peoples of the Western Amazon, where animistic cosmologies are the norm, relationships between human and other-than-human are mediated by various forms of communication. In this paper, I examine a type of shamanic song called “icaro”, found in Western Amazonian indigenous and mestizo communities. Using examples from the ethnographic literature, I discuss the acquisition and use of these shamanic songs to communicate with spirits and to e ect change in the material world. Then, using the theory of phytosemiotics in conjunction with new research into plant communication, I show how the process of shamanic apprenticeship and the acquisition of icaros is a form of inter-species communication in which the apprentice intercepts and interprets the phytochemical signals inherent in plant communicative processes.