This project will be the first to examine the history of botany in the Philippines under two successive colonial regimes—Spanish and U.S. The history entails an investigation of two colonial scientists, the institutional contexts in which they worked, the local informants who collaborated with them, and the science that they produced. Furthermore, as historical studies of science in the Philippines have almost completely relied on European-language documents, I seek to offer a new angle of vision into the history of Philippine botany with the use of Tagalog-language material alongside Spanish and English sources. This will bring light to local botanical traditions that circulated during the colonial transition and will animate the critical role played by local informants in scientific projects typically associated with the colonial state. While botany may be neutrally understood as the study of plants, in the colonial Philippine context it was a highly contested discipline, substantively influenced by competing imperialist and nationalist aims. With the arrival of the U.S. colonial administration to the Philippines in 1898 came the establishment of institutions of botanical research and the emergence of historical writing that derided Spanish science as a-empirical and exceedingly religious. Yet botany was the premier science of the Spanish Empire, and U.S. scientists relied on Spanish publications and institutions to grapple with the vast diversity of Philippine flora. My project is an interdisciplinary investigation of this historiographical distortion and a recuperation of Spanish and local Philippine scientific discourse. An exploration of this transitional moment in Philippine history demonstrates how botany must be considered a science of territorial claims, deployed to serve metropolitan interests, imperial contestations, and local assertions of nationhood.