A Cladistic Outline of the Eumycota

Abstract- A cladistic classification of fungi determined by a parsimony method with 21 terminal taxa and 51 characters is presented. Outgroup comparison with Oomycetes determined polarity assessments. The group Eumycota, including the traditional taxa Hyphochytriomycetes, Chytridio-mycetes, Zygomycetes, Ascomycetes and Basidiomycetes, is defined by two synapomorphies, molecular weight of 25S RNA, and chitin cell walls. Some groups are supported as monophyletic; Eumycota, Amastigomycota, Dicaryomycotina, Ascomycetes, Protobasidiomycetes, Basidiomycetes, Euascomy-cetidae, Hymenomycetidae and Homobasidiomycetales. The Hyphochytriomycota is the sister group to remaining groups. The Taphrinaceae and Saccharomycetaceae are more closely related to the Basidiomycetes than to any of the ascomycetous groups. In the absence of unique character sets groups such as the Mastigomycotina, Hemiascomycetes, Ustomycetes, Holobasidiomycetes, Heterobasidio-mycetes, Phragmobasidiomycetes and the Teliomycetes cannot be maintained and are abandoned as paraphyletic. Characters and terminal taxa used for the analysis are defined and discussed.