This contribution reports on a series of studies carried out on archaeological plant remains recovered from sites located in northwestern Argentina. These archaeological sites correspond to different chronological moments and social organizations. The materials analyzed are mainly carpological remains of different taxa (different species of Phaseolus, Capsicum, Nicotiana, Cucurbitaceae, Solanum, Chenopodiaceae, Amaranthaceae, and Malvaceae, among others). Morphometric, anatomical, and genetic analyses allowed us to propose the presence of wild-weedy-crop complexes, including weeds, hybrids, and intermediate forms. In addition, several past uses were identified: food, medicine, fodder, and ritual, among others. The former opens up an understanding of management practices, domestication, and ways of relating to plants that goes beyond linear approaches from “simple” to “complex” practices, as well as breaking with dichotomous views between wild and domesticated. Furthermore, the inclusion of weeds and psychoactive plants allows for an understanding that is not only anchored in subsistence and adaptive fitness only. In this way, this chapter aims to enrich the knowledge of archaeological plant diversity and past management practices in northwestern Argentina, as part of the Southern Andean region, echoing those currently being developed by the region’s indigenous populations.