Wouter Klein is Plant Humanities fellow at Dumbarton Oaks. A historian from the Netherlands, he received his PhD from Utrecht University in 2018. He is interested in the interconnected history of medicine, pharmacy, and botany in the early modern period; the circulation of knowledge and commodification processes of therapeutic drugs; and digital research methods to study medical practices of the past over the long term. He has a particular interest in the availability of materia medica in the past, either as commercial goods in trade records, research specimens for academic physicians, or commodified products for the general public. His research aims to unravel the question of how the global dimensions of commerce, science, and society helped some non-European natural substances become major commercial ingredients for medicines while others had much less success in the early modern medical marketplace. To tell those stories, his research makes use of large collections of digital historical data, like private correspondence, pharmaceutical manuals, auction records, and newspaper advertisements.