A molecular re-appraisal of taxa in the Sordariomycetidae and a new species of Rimaconus from New Zealand

Several taxa that share similar ascomatal and ascospore characters occur in monotypic or small genera throughout the Sordariomycetidae with uncertain relationships based on their morphology. Taxa in the genera Duradens, Leptosporella, Linocarpon, and Rimaconus share similar morphologies of conical ascomata, carbonised peridia and elongate ascospores, while taxa in the genera Caudatispora, Erythromada and Lasiosphaeriella possess clusters of superficial, obovoid ascomata with variable ascospores. Phylogenetic analyses of 28S large-subunit nrDNA sequences were used to test the monophyly of these genera and provide estimates of their relationships within the Sordariomycetidae. Rimaconus coronatus is described as a new species from New Zealand; it clusters with the type species, R. jamaicensis. Leptosporella gregaria is illustrated and a description is provided for this previously published taxon that is the type species and only sequenced representative of the genus. Both of these genera occur in separate, well-supported clades among taxa that form unsupported groups near the Chaetosphaeriales and Helminthosphaeriaceae. Lasiosphaeriella and Linocarpon appear to be polyphyletic with species occurring in several clades throughout the subclass. Caudatispora and Erythromada represented by single specimens and two putative Duradens spp. have unclear affinities in the Sordariomycetidae.Taxonomic novelties:Rimaconus coronatus Huhndorf & A.N. Mill., sp. nov.