Archaeologists working in the Late Formative Lake Titicaca Basin have identified several “transit communities”—villages that benefited from long-distance exchange. Some scholars suggest that such places played a key role in the development of the Middle Horizon city of Tiwanaku. In this article, we explore the movement of plant goods into transit communities during both the Late Formative (300 BC–AD 500) and Middle Horizon (AD 600–1100) periods. After presenting the current understanding of transit communities, we summarize previous work on both local plants, including tubers and quinoa, and the presence of maize. We then report on a recent microbotanical study of ceramics recovered from excavations at Late Formative Challapata (in the eastern basin) and a burial from the Middle Horizon occupation at Chiripa (in the southern basin). For the first time we identify lowland tubers in the Lake Titicaca Basin, including yuca, sweet potato, and arrowroot. These findings reveal the critical importance of microbotanical analyses for tracing regional connections and foodways in emergent Middle Horizon worlds, as well as the need for more complex interpretive models for things/plants-in-motion.