Exobasidiomycetes is a class of fungi within the phylum Basidiomycota, primarily known for including plant pathogens that cause diseases such as leaf and flower galls, smuts, and witches’ brooms. Members of this class are mostly obligate parasites, infecting vascular plants and often showing high host specificity. They are characterized by a simple, often yeast-like or filamentous morphology and a lifecycle that includes both asexual and sexual reproduction. Exobasidiomycetes play significant ecological and economic roles because their infections can impact agricultural crops and ornamental plants, while also contributing to studies of host-pathogen interactions and fungal evolution.