jats:p This essay situates the French Jesuit missionary Joseph-François Lafitau's (1681–1746) ‘discovery’ of Canadian ginseng within its social, commercial and religious contexts, and illustrates how the missionary's upbringing and education in France shaped the way he perceived nature in the New World. It elucidates the manner in which Lafitau ‘Galenized’ Canadian flora, fauna and peoples. It explores the role of Lafitau's dual enculturation in both a mercantile household and later the Society of Jesus in his application of Galenic categories to Canadian nature. The essay then examines the tensions between localism and universalism in Galenic medicine in the eighteenth century. It links these dichotomies to Lafitau's Galenization of Canadian ginseng. Finally, it suggests that since the Jesuits were prohibited from trading goods they had jats:italicpurchased</jats:italic> , they sold medicinal plants they had jats:italiccultivated</jats:italic> themselves, which played a central role in financing the Society's missions in a manner they believed to be morally acceptable. </jats:p>