Three new species of Hyphodontia with peg-like hyphal aggregations

Descriptions, illustrations and phylogenetic analyses for three new taxa of Hyphodontia (Basidiomycota) are provided. Hyphodontia astrocystidiata sp. nov. was collected from warm-temperate mountain forests of Taiwan; H. microfasciculata sp. nov. was found in subtropical Taiwan, southern China, and northern Vietnam; H. vietnamensis sp. nov. was described from northern Vietnam. All three species have sterile projecting peg-like structures, consisting of encrusted hyphae. Hyphodontia astrocystidiata is characterized by Resinicium-like astrocystidia on subicular hyphae and astrocystidia-like hyphal ends in hymenium. Hyphodontia microfasciculata is distinguished by its small-sized ellipsoid spores and fine emergent fascicles composed of thin-walled, flexuous hyphae. The features of H. vietnamensis are subulate cystidia, cylindrical spores, and projecting, densely arranged slender clusters of acuminate hyphae. The morphology of crystal deposits on projecting hyphae in these three species was studied by means of scanning electron microscopy. Molecular phylogeny analyses were performed by maximum parsimony and Bayesian methods, both based on sequences of the internal transcribed spacer region of nuclear ribosomal DNA. The phylograms from both analyses confirm independent specific status of H. microfasciculata and H. vietnamensis. The former species sits in a subclade with Hyphodontia sambuci, the latter species is in another subclade with H. crustosa. Hyphodontia astrocystidiata is placed close to Schizopora paradoxa, but the two species are distinct in terms of morphology.