The family Pleosporaceae is a large and diverse group of fungi within the order Pleosporales (class Dothideomycetes, phylum Ascomycota). Members of this family are mostly saprobic, living on decaying plant material, but some are plant pathogens, causing leaf spots, stem cankers, and other diseases. They are characterized by producing pseudothecial ascomata (flask-shaped fruiting bodies), bitunicate asci (double-walled spore sacs), and dark, multicellular ascospores often with septa. Pleosporaceae fungi are ecologically important for decomposing organic matter and nutrient cycling, and several genera within the family, such as Alternaria and Pleospora, are significant in agriculture due to their impact on crops. Their study is essential for understanding both fungal biodiversity and plant disease management.