This article examines Yanomami knowledge as a decolonial epistemology of the forest and, secondarily, places it in dialogue with Maya mythic memory in order to argue that Indigenous cosmologies should be understood as complex ontological systems rather than residual forms of folklore. Drawing on Enrique Dussel’s concept of the mythic-ontological core and the decolonial critiques of Aníbal Quijano, Ramón Grosfoguel, Walter Mignolo and related authors, the text analyzes how myth, symbolism, ritual and historical memory organize Indigenous visions of nature, personhood, illness, aesthetics and territory. The discussion is based on a critical rereading of ethnographic and bibliographic materials on Yanomami ethnobotany, shamanic medicine, edible mushrooms, women’s basketry, the fungus përisi, and the political-ecological denunciations formulated by Davi Kopenawa and allied researchers. The article argues that Yanomami thought expresses a sophisticated relational ontology in which forest, body, spirit, community and territory constitute a living totality. From this perspective, the destruction of the forest represents simultaneously ecological devastation, ontological aggression and epistemic violence. The text further argues that the category of planetary thought can be reconfigured from Indigenous perspectives—not as a new universalism, but as a pluriversal horizon grounded in reciprocity, alterity and the defense of life. By foregrounding Yanomami knowledge and placing it in comparative dialogue with Maya historical memory, the article proposes an intercultural and interscientific agenda capable of renewing anthropology, environmental ethics and intercultural education in Latin America.