Adaptive introgression, the transfer of useful alleles from one species to another through hybridization and backcrossing, is hypothesized to introduce new genetic diversity which could help plants expand into new habitats and respond to environmental change. With increasing awareness that hybridization is common across the plant Tree of Life, major questions have arisen, including: which genes are most likely to be exchanged between species, and how do these affect the evolution of hybridizing lineages, especially adaptation to new environments? However, little is still known about the genomic distribution and content of introgressed regions outside of a few model systems. In this study, we aimed to determine the effects of hybridization on Eucalyptus globulus by characterizing introgressed genomic regions donated from a Tasmanian endemic species, Eucalyptus cordata. Previous work has shown that morphologically typical E. globulus trees growing in close proximity to small populations of E. cordata have captured chloroplast DNA and some nuclear markers. It is possible that these alleles have been retained for over 17,000 years because they have conferred an advantage for the introgressant Eucalyptus trees. In a first step to testing the adaptive value of hybridization in this system, we use whole-genome resequencing and admixture analysis to map the mosaic nature of the E. globulus genome. With that information, we address the following questions: 1) which genomic regions and genes are most likely to be introgressed and 2) to what extent does selection, positive or negative, play a role in introgression in comparison to neutral processes?