In the early decades of the twentieth century, the Smithsonian Institution, in collaboration with the U.S. National Academy of Sciences and various federal agencies, sought to oversee the preparation of a Philippine flora; that is, a taxonomical catalogue of the islands’ botanical riches.  Boosters originally conceived of the project in 1903 as a means of showcasing U.S. colonial prowess and solidifying the global status of the United States as a world power.  Philippine nationalism and U.S. policies of Filipinization prompted a more universalist rationale for the flora couched in the rhetoric of international science, but colonial hierarchies persisted in American conceptions of custody over Philippine botanical specimens.  The U.S. quest for a Philippine flora reveals the tangled combination of competing nationalisms, civilizational discourses, and colonial anxieties that shaped the American empire and its entry into the global history of imperial botany.