Abstract This article studies human-plant relations as technical phenomena in the context of the pluriethnic communities of the border between Brazil and Guyana. It proposes that we consider a technogenesis of the social at the intersection of technical processes and vital flows of manioc stems - the overground part of the plant that produces manioc (Manihot esculenta). Its starting point is a Wapichana agriculturalist’s collection of stem segments. The onomastics of this set provides an idea of the diversity of these plants in the region. However, the article argues that, rather than being referents in a closed classificatory system, names are histories, indexes of ways of knowing and processes of individuation of people and varieties. By emphasising processes of stem manipulation, the article discusses some of the methodological challenges of the ethnography of technique and reflects on contemporary social transformations in dialogue with Indigenous analyses.