Arthoniomycetes are a class of ascomycete fungi. It includes two orders: Arthoniales and Lichenostigmatales. Most of the taxa in these orders are tropical and subtropical lichens.

Systematics

Phylogenetic analysis supports the monophyly of this class. Dothideomycetes is a sister group.

Characteristics

Taxa have apothecia, cup- or saucer- shaped ascoma in which the hymenium is exposed at maturity. These apothecia are bitunicate - with clearly differentiated inner and outer walls.