Dothideomycetes

Dothideomycetes is the largest and most diverse class of ascomycete fungi, comprising 11 orders, 90 families, about 1,300 genera and more than 19,000 known species. Most members develop through an ascolocular process in which reproductive pockets form within fungal cells before sexual structures develop, typically producing flask-shaped pseudothecia containing bitunicate asci that release spores by bursting. Ecologically the class includes notable plant pathogens such as the apple scab fungus, but most species live as endophytes or saprobes on decaying wood and organic matter, with a smaller number forming lichens or, in one case, a mycorrhizal association.