Abstract
Members of the family Saccotheciaceae are found in various environments and have different lifestyles. While exploring Mimosa tenuiflora-associated endophytic fungi in the Caatinga dry forest in Brazil, the isolates were initially identified as aureobasidium-like fungi. Based on morphological features and phylogenetic analyses using ITS, LSU, tub2, rpb2, and tef1 gene sequences, these endophytes were placed within a distinct clade in Saccotheciaceae, differing from the genera currently accepted in the family. Here, we describe a new genus, Paivomyces gen. nov. (including Paivomyces mimosae sp. nov.). Additionally, during our phylogenetic analyses, we observed that Selenophoma australiensis, described from leaves of Eucalyptus mineata in Australia, could be treated as a unique lineage among the genera in the family Saccotheciaceae. Herein, we introduce Pseudoselenophoma gen. nov. (including Pseudoselenophoma australiensis comb. nov.) to accommodate the species. Our findings improve our understanding of the fungal diversity in the Caatinga dry forest in Brazil and clarify the phylogenetic lineages of Saccotheciaceae. Citation: Nascimento SS, Ferro LO, Silva EA, Felipe MTC, Souza-Motta CM, Bezerra JDP (2025). Introducing two new genera, Paivomyces gen. nov. and Pseudoselenophoma gen. nov., in Saccotheciaceae (Dothideales). Fungal Systematics and Evolution 16: 55-69. doi: 10.3114/fuse.2025.16.4.