More than 95% of plant-pathogenic, lichenic, lichenicolous, endophytic, and endolichenic fungi are filamentous Ascomycota, concentrated in the Pezizomycotina. The evolution of this clade is powerfully linked with the evolution of the green tree of life. To better understand the evolution of plants and fungi it is therefore vital to integrate data layers pertaining to symbioses into the Pezizomycotina tree, including host associations, the degree of specificity/generalism of occurrence and function, and the trophic nature of species interactions. Given the importance of the Pezizomycotina to all aspects of ecosystem function and their potential applications in agriculture, industry, and medicine, a new phylogenetic context for Pezizomycotina is urgently needed.