Plant circulation in Portuguese America and Independent Brazil was significantly indebted to the French colonial network, during the Napoleonic wars as well as from 1815. French Guiana, that share borders with Brazil, was under many circumstances a strategic element for the transfer and the acclimatization of exotic plants in Americas. Exchanges of seeds and natural products could be spontaneous or intentional. From the last decades of the eighteenth century, the role of botany became more evident in regard to plant transfers. The French naturalist Auguste de Saint-Hilaire collaborated to establish a type of botanical knowledge that, from the beginning of the nineteenth century, became a requirement for anyone who would identify, classify or acclimatize plants.