Hymenoscyphus corni-maris and H. corni-sanguineae spp. nov. (Helotiaceae) on Cornus mummified fruits in Europe and Asia

Two morphologically similar fructicolous species are here assigned to the genus Hymenoscyphus. However, they exhibit a high level of genetic divergence. They form short- to long-stipitate apothecia on fallen pits of Cornus spp. One of them, H. corni-maris, was found exclusively on C. mas so far, while H. corni-sanguineae was recorded in Europe on C. sanguinea and in China on C. controversa. The two species share an ectal excipulum of textura prismatica(-porrecta), living paraphyses containing refractive vacuolar guttules, euamyloid ascus apical rings of the Hymenoscyphus-type, and ciborioid ascospores of similar size and low lipid content. Hymenoscyphus corni-maris differs from H. corni-sanguineae by a white vs. yellowish-ochraceous disc and asci arising from croziers vs. simple septa, respectively. No sporulation was observed in pure culture of both species. Two synonymous names exist in the literature. Sclerotinia corni from Czechia on C. mas is illegitimate (Art. 3.1) as it is a later homonym of a species now recognised as Monilinia corni. Lanzia glandicola var. cornicola from China on C. controversa was published at the varietal level only. Both synonymies were clarified by reexamination of the holotypes and by DNA sequence analysis in L. glandicola var. cornicola. Based on our phylogenetic analysis of ITS + LSU rDNA, H. corni-maris clustered in a strongly supported subclade comprising different anamorph- and teleomorph-based taxa, which were recently recognised as a new family, Tricladiaceae. Hymenoscyphus corni-sanguineae nested in another strongly supported clade that comprises species such as H. repandus and H. menthae, as well as two monotypic genera, the cleistocarpous Amylocarpus and the anamorphic Goniopila. Except for the latter two taxa, all these clades have morphologically similar apothecia and can hardly be separated into different groups based on their teleomorphs. For this reason, we prefer to adopt Hymenoscyphus in a broad, paraphyletic sense.