Taphrinomycotina
The Taphrinomycotina are one of three subdivisions constituting the Ascomycota and is more or less synonymous with the slightly older invalid name Archiascomycetes. Recent molecular studies suggest that the group is monophyletic and basal to the rest of the Ascomycota.
The major taxa are Schizosaccharomycetes, Taphrinomycetes, Neolectomycetes, and Pneumocystis.
The Schizosaccharomycetes are the yeasts that reproduce by fission rather than budding, unlike most other yeasts, many of which are in the subdivision Saccharomycotina.
The Taphrinomycetes are dimorphic plant parasites with both a yeast state and a filamentous state in infected plants. They characteristically infect leaves, catkins, and branches, not roots. Taphrinomycetes form asci but no ascomata.
The Neolectomycetes are species in a single genus, Neolecta, which are the only members of the subdivision that form ascomata, and which specifically grow out of root tips. They may have a yeast state.
The Pneumocystidomycetes also encompasses only one genus of yeasts, Pneumocystis, one of which causes Pneumocystis pneumonia in humans by developing cysts on the lung tissue.
None has ascogenous hyphae giving rise to the asci.
