The ascomycete system

The ascomycete system, that is developed here, is based on both molecular and morphological criteria. Three subphyla, 13 klasses and three subclasses are currently recognized. Several of these taxa are not supported by high bootstrap values in phylogenetic analyses and are possibly not monophyletic. Some taxonomists maintain that only monophyletic goups should be given names in classifications. However, for practical reasons, we prefer to use provisional names for some taxa that repeatadly appear as clades in phylogenetic studies, but without strong bootstrap support, e.g. the operculate discomycetes, the class Pezizomycetes. Most of the discolichens are disposed on two classes, Lecanoromycetes and Arthoniomycetes, distinguished by morphological characters, but only the latter is supported by molecular data.

The higher taxa are recognized in the sense of Eriksson & Winka (1998), but the circumscription of several of these taxa will change, and the author(s) of a new accepted concept will be cited after the Latin name, with a reference to the source.

The names for the suprageneric taxa are always based on a generic name, e.g. Saccharomycotina, Sordariomycetes, Dothideomycetes, not Hemiascomycotina, Pyrenomycetes, Loculoascomycetes (we have given some of the alternative names within parenthesis). The latter names are acceptable according to the International Code of Botanical Nomenclature, but there are advantages in using names for higher taxa that are based on names of genera. By this, each taxon is connected to type specimen. This eliminates the current ambiguity about the application of names for higher taxa, and if split, the name be retained, though in a new sense..

The following is an overview of the higher taxa of Ascomycota (P = paraphyletic, M = monophyletic).

Phylum ASCOMYCOTA

Taphrinomycotina (syn. Archiascomycotina) - P?

• Neolectomycetes - M
• Pneumocystidomycetes - M
• Schizosaccharomycetes - M
• Taphrinomycetes - M

Saccharomycotina (syn. Hemiascomycotina) - M

• Saccharomycetes - M

Pezizomycotina (syn. Euascomycotina) - M?

• Arthoniomycetes - M
• Chaetothyriomycetes - M
• Dothideomycetes - P?
• Eurotiomycetes - M
• Laboulbeniomycetes - M
• Lecanoromycetes - P?
• Leotiomycetes - P?
• Orbiliomycetes - M
• Pezizomycetes - M
• Sordariomycetes - M
  Hypocreomycetidae - M?
  Sordariomycetidae - P?
  Xylariomycetidae - M
• Spathulosporomycetes - M
  

Updated by Ove E. Eriksson on February 22, 2002 (ove.eriksson@eg.umu.se).