Dothideomycetidae Pleosporomycetidae Incertae sedis Dothideomycetes is the largest and most diverse class of ascomycete fungi.

After several DNA sequence comparisons it is now clear that another group of fungi which share these characteristics are distantly related.

The best known members of this class are several important plant pathogens (like Phaeosphaeria nodorum and Venturia inaequalis).

However, a majority of described species are either found as endophytes or saprobes growing on woody debris, decaying leaves or dung.

A smaller number exist as lichens[8] and a single species, Cenococcum geophilum, can form mycorrhizal associations with plant roots.