Endophytic fungi are common and diverse in plants. Yet the nature of their interactions with host plants, and how these interactions cascade upward to communities and ecosystems, is largely unknown. In the first book of its kind, Gregory P. Cheplick and Stanley H. Faeth synthesize existing studies of endophyte-grass symbioses within the context of modern ecological and evolutionary concepts. The authors cover a broad range of topics including the effects of endophytes on herbivory, host growth, physiology, reproduction, and competitive ability in a variety of grasses and environments. Clearly and engagingly written, Ecology and Evolution of the Grass-Endophyte Symbiosis highlights the most essential aspects of symbiosis ecology and evolution while suggesting avenues for future research.