Placement of Medeolaria farlowii in the Leotiomycetes, and comments on sampling within the class

Abstract

Medeolaria farlowii, an ascomycetous parasite of Medeola virginiana, has been included as the only member of the family Medeolariaceae and order Medeolariales. Its assignment within the Ascomycota has been problematic due to the lack of distinctive ascomatal form and ascus morphology. Asci are formed in a loosely organized hymenium on hypertrophic portions of Medeola virginiana stems. Phylogenetic analyses of nuclear 5.8S, large subunit, and small subunit rDNA gene sequences place M. farlowii in the Leotiomycetes with parsimony, Bayesian, and maximum likelihood analyses, but its position within this class remains unresolved. In general, limited taxon and gene sampling in the Leotiomycetes hampers placement of taxa within this class. A survey of available sequence data in the Leotiomycetes is given, and the implication for phylogenetic studies within the class is discussed. Medeolaria farlowii should be treated as a monotypic genus in the monotypic order Medeolariales, class Leotiomycetes.