Fungal biodiversity is among the most threatened on the planet due to ongoing climate change, which is often overlooked. As one of the largest established kingdoms, fungi still have an incomplete species list, and many species will likely disappear before they are even discovered. The world is training fewer and fewer mycological taxonomists, slowing down the collection of fundamental information and research on this group. One solution is to bring together experts to compile and update bibliographies with revised information on various aspects of mycology. This work was undertaken to address topics such as taxonomy, biodiversity, and fungus-host relationships (including endophytes, phytopathogens, and mycorrhizae). The chapters bring together both classic themes and recent research advancements. This book aims to help bridge the significant knowledge gap regarding these often-overlooked yet essential organisms.