Pucciniomycetes (formerly known as Urediniomycetidae) is a diverse class of fungi in the subphylum Pucciniomycotina of phylum Basidiomycota. The class contains 5 orders, 21 families, 190 genera, and approximately 8,016 species. It has been estimated that this class contains about one third of all teleomorphic basidiomycetes. Pucciniomycetes contains many economically important plant pathogenic fungal rusts; the order Pucciniales (formerly Uredinales) is the largest clade in this class, representing approximately 7,000 species.

Pucciniomycetes are cosmopolitan and can be found in both terrestrial and aquatic environments, although aquatic species are poorly understood.

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