Molecular phylogeny and morphology reveal two new bamboo-rotting species of Favolaschia (Mycenaceae, Agaricales) from China

Favolaschia is a poroid fungal genus within family Mycenaceae (Agaricales) , exhibits a global distribution and is predominantly found across tropical and subtropical regions. During an investigation of bamboo-rotting fungi in China, two unknown species of Favolaschia were collected and subsequently confirmed as new to science based on morphological and molecular phylogenetic analyses. Phylogenetic relationships were inferred from a concatenated dataset of ITS and nLSU sequences. Both new species nest within Favolaschia sect. Anechinus . Favolaschia nana is characterized by its producing extremely small basidiomata, with less than 12 pores, the presence of cheilocystidia and diverticulate terminal cells in pileipellis, and broadly ellipsoid basidiospores measuring 6–9 × 4.3–6.5 µm. Favolaschia rotundipora is characterized by reniform to semicircular basidiomata with rounded mature pores, the absence of cheilocystidia and presence of diverticulate terminal cells in pileipellis, and broadly ellipsoid basidiospores measuring 6–8.9 × 4.7–7.5 µm. Detailed morphological descriptions and a comparison with morphologically similar and phylogenetically allied species are provided. This study increases the recognized species diversity of Favolaschia in China and contributes to a better understanding of the taxonomy and phylogeny of this genus.