From Local Collectors to Global Science: Hidden Histories of the Kew Herbarium

John Schaefer, University of Cambridge in collaboration with the Royal Botanic Gardens, Kew, United Kingdom This paper examines the interplay of science and globalisation through nineteenth-century British plant specimen exchange, focusing on the herbarium of the Royal Botanic Gardens, Kew as a key case study. Applying social network analysis as an exploratory lens illuminates the overlooked contributions of local collectors, labourers, and intermediaries in the transcontinental movement of plants and knowledge. Central to imperial science, the Kew Herbarium housed plant specimens acquired through colonial networks, representing complex relationships and power dynamics. Yet historical narratives often privilege figures like William Hooker, his son Joseph Hooker, and Joseph's son-in-law William Thiselton-Dyer, whose combined directorships from 1841 to 1905 marked a period of significant expansion and collecting activity at Kew. By decentering these figures, this study maps the broader networks of individuals and institutions underpinning botanical exchange. A focus on nineteenth-century Australian plant-collecting networks underscores the interdependence of these colonial actors, who both navigated and actively contributed to evolving nomenclatural and classificatory systems. Combining archival research with social network analysis, the study explores transcontinental patterns of plant collecting, leveraging specimen label data to visualise connections between collectors. Network analysis thus provides a guided means of reading, and conversely, close reading informs the development of more nuanced and focused quantitative approaches in the history of science. Foregrounding the contributions of local collectors, horticulturalists, and other intermediaries, this paper challenges the perception of Kew as the sole locus of British botanical progress and illustrates how the digitisation of scientific plant specimens yields a novel lens for surveying Kew's colonial archives. Speaker biography John Schaefer is a PhD student in History and Philosophy of Science at the University of Cambridge, working in collaboration with the Royal Botanic Gardens, Kew. His research focuses on the history of botany, empire, and plant collecting, with a particular emphasis on integrating digital humanities methods. As a 2024 U.S. Fulbright Scholar, John explored these themes in the Australian context at Western Sydney University. His doctoral project now reconstructs and analyses the social networks of colonial plant collectors in the late nineteenth century, using Kew Herbarium specimen data to explore the global dynamics of plant and knowledge exchange.