Abstract
Fungi represent a kingdom of life with vast, undiscovered diversity. In the unique man-made ecosystem of the Kunming World Horticultural Expo Garden, a site with remarkable plant diversity, four fungal strains were isolated from diseased branches of two widely cultivated plants, Olea europaea (olive) and Nandina domestica. Through a comprehensive analysis integrating morphological characteristics and multi-locus phylogenetic data (including LSU, SSU, ITS, rpb2, tef1-α, and tub2 sequences), we identified two new species: Oedohysterium oleae and Melomastia kunmingensis, both of which are phylogenetically and morphologically distinct from known species. Furthermore, we report M. kevinhydei as a new host record on O. europaea, suggesting a broader host range for this species, and, for the first time, document the sexual morph of the type species Parapyrenochaeta protearum, providing crucial morphological insights for this genus, previously known only in its asexual state. These findings underscore the immense value of unique horticultural environments as reservoirs of fungal diversity.