As its record in California, southern India, and elsewhere suggests, of the many biotic exchanges of the long nineteenth century, the case of the Australian blue gum tree ( Eucalyptus globulus ) is one that especially transcends bilateral, spatial, or imperial framing. The blue gum instead invites more material and temporal perspectives to its spread: since its reputation accrued over time in diverse colonial settings, its adoption was contingent on the extent to which local tree cover was feared to have been depleted, and its growth was hoped to secure the futures of colonial states. Focusing on nineteenth-century understandings of the biological characteristics of the blue gum in southeastern Australia, South Asia and California, and the circulation of this knowledge between these sites, this article draws on the insights of neo-materialism to argue that this tree’s value and importance lay in its perceived ability to rapidly provide fuel wood for the empowerment of colonial states. This article is part of the “Crossroads of Indo-Pacific Environmental Histories” special issue of Pacific Historical Review.