Two new species of Resupinatus (Resupinataceae, Agaricales) from China

Within the typical saprotrophic genus Resupinatus, only 47 species are currently recognized worldwide. Most of these species are reported from Europe and North America, whereas only 12 species have been recorded from China. Species of Resupinatus are characterized by laterally or dorsally attached basidiomata, sessile or with a lateral pseudostipe, a gelatinous pileus, smooth and inamyloid basidiospores, cylindrical to coralloid cheilocystidia with apical protrusions, and pileipellis hyphae with branches or protrusions.

They usually occur on dead branches and well-decayed wood in mixed coniferous and broad-leaved forests. In this study, two new species, R. meihui sp. nov. and R. cinereofuscus sp. nov., are recognized from China. Both species are laterally or dorsally attached to the substrate, sessile, and have lamellate hymenophores, pileus surfaces covered with tomentum or pruina, and cheilocystidia with digitate protrusions.

However, R. meihui is distinguished by the absence of coarse felt at the point of attachment, the presence of shortly branched lamellae, and coralloid protrusions on the terminal hyphae of the pileipellis, whereas coarse felt at the point of attachment, unbranched lamellae, and smooth, thick-walled terminal hyphae in the pileipellis are observed in R. cinereofuscus. Morphological descriptions, habitat photographs, micrographs, and line drawings are provided for the two species, and their differences from related taxa are discussed.

Phylogenetic trees inferred from ITS and nrLSU sequences using Bayesian inference and maximum likelihood analyses show that both species form independent lineages with strong support. A key to the 49 known species of Resupinatus is also provided.