In this article, the multifaceted relationship between colonial power and scientific knowledge is analysed. The specific focus is on untangling the contested and symbiotic connections between colonialism and the emergence and consolidation of aspects of botanical science. Colonial imperatives and the social consequences of colonial rule in India constituted the context for the idea and project of botanical gardens that facilitated the global transfer of a variety of plants to India. It was in the process of dealing with the problems of the transfer of plants across very diverse ecological and social contexts that natural history was eventually transformed into formal botanical science both in India and in Europe. Particular forms of scientific knowledge and institutions were indispensable for the consolidation of empire even as they facilitated new imperial concerns and projects that constituted the structural context for the development of new forms of scientific knowledge, practices, institutions and power. Without reducing science to nothing more than an appendage of colonial power and imperatives, the significance of empire in the rise of botany as a formal science is analysed in this article.