In his writings, Francis Bacon emphasized the interrelatedness between the migration of people and knowledge, arguing that Europeans of his time had surpassed the greatest civilizations because of their ability to traverse the world freely. Concentrating on Spanish observers who investigated New Spain’s flora, this article bridges theory and practice by examining the Iberian roots of Bacon’s views. The article examines scientific approaches for acquiring bioknowledge by Iberians who specialized in European medicine, including Francisco Hernández, Juan de Cárdenas and Francisco Ximénez. While the article recognizes the contribution of travellers and expatriates to Spain’s bioprospecting project, it also points to the ways in which the limitations of the transfer of botanical information was acknowledged and discusses its meaning. By presenting the complexities in the communication of knowledge, I argue, naturalists in the colonies could highlight their unique vantage point in relation to “armchair” specialists in the metropole.