Assessing the phylogenetic placement and redundancy of Aspidotheliaceae (Ascomycota), an orphaned family of lichen-forming fungi

Abstract

The lichen-forming fungal genus Aspidothelium has either been considered to represent a separate genus and family or a synonym of Thelenella in Thelenellaceae. At times, a close relationship has been suggested with genera now placed in Celotheliaceae, Monoblastiaceae, Porinaceae, Protothelenellaceae, Pyrenulaceae, Strigulaceae, Thelenellaceae, and Verrucariaceae, families scattered across three ascomycete classes. Consequently, its classification has remained unstable, and the genus is currently listed as incertae sedis within Ascomycota. Here we utilize DNA sequence data to clarify its position. Our sampling suggests that Aspidothelium is embedded within the family Thelenellaceae (Lecanoromycetes: Ostropomycetidae), supporting previous proposals to synonymize Aspidotheliaceae with Thelenellaceae. This clade is allied with the order Ostropales and further work is needed to elucidate whether it should be considered part of Ostropales or a distinct order. Aspidothelium is monophyletic, and its continued recognition requires acceptance of the genus Chromatochlamys. The abandonment of historic classification schemes resulted in the proliferation of many orphaned clades of perithecial, lichen-forming fungi – the present study has clarified the higher-level relationships of one of these enigmatic families, and facilitated its placement in a modern phylogenetic framework.

Key words:

• crustose
• foliicolous
• Ostropomycetidae
• perithecia
• systematics
• Thelenellaceae
• tropics

Acknowledgements

We are grateful to a number of organizations for funding including: NSF-DEB 0715660 ‘Neotropical Epiphytic Microlichens – An Innovative Inventory of a Highly Diverse yet Little Known Group of Symbiotic Organisms' to The Field Museum (PI Robert Lücking), NSF-DEB 0717476 ‘Systematics of Dothideomycetes' to The Field Museum (coPI Thorsten Lumbsch; PI: J. Spatafora), a grant from the Committee on Evolutionary Biology, University of Chicago to Matthew Nelsen, and the Caterpillar® company provided funds to study lichens from Panama. Most DNA analyses were performed at the Pritzker Laboratory for Molecular Systematics and Evolution at the Field Museum.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We are grateful to a number of organizations for funding including: NSF-DEB 0715660 ‘Neotropical Epiphytic Microlichens – An Innovative Inventory of a Highly Diverse yet Little Known Group of Symbiotic Organisms' to The Field Museum (PI Robert Lücking), NSF-DEB 0717476 ‘Systematics of Dothideomycetes' to The Field Museum (coPI Thorsten Lumbsch; PI: J. Spatafora), a grant from the Committee on Evolutionary Biology, University of Chicago to Matthew Nelsen, and the Caterpillar® company provided funds to study lichens from Panama. Most DNA analyses were performed at the Pritzker Laboratory for Molecular Systematics and Evolution at the Field Museum.