Ants are probably the most dominant insect group on Earth, representing 10–15 percent of animal biomass in terrestrial ecosystems. Flowering plants, meanwhile, owe their evolutionary success to an array of interspecific interactions—such as pollination, seed dispersal, and herbivory—that have helped to shape their great diversity. This book brings together findings from the scientific literature on the coevolution of ants and plants to provide a better understanding of the unparalleled success of these two groups, of interspecific interactions in general, and ultimately, of terrestrial biological communities. It synthesizes the dynamics of ant–plant interactions, including the sources of variation in their outcomes. The book captures both the emerging appreciation of the importance of these interactions within ecosystems and the developing approaches that place studies of these interactions into a broader ecological and evolutionary context.