Albatrellus mongolicus sp. nov. (Albatrellaceae, Russulales) from Liaoning Province, NE China

The genus Albatrellus, a prominent group of stipitate terrestrial fungi in the order Russulales, is of considerable ecological and economic importance. In this study, we describe a species, Albatrellus mongolicus sp. nov., from Liaoning Province, northeastern China, based on combined phylogenetic analyses, including the internal transcribed spacer regions (ITS), the large subunit nuclear ribosomal RNA gene (nLSU), the translation elongation factor 1-α gene (tef1-α), the largest subunit of RNA polymerase II (rpb1), as well as detailed morphological examination. Phylogenetically, A. mongolicus formed a well-supported lineage with A. cantharellus and A. shouxiangu. Morphologically, it is characterized by annual, terrestrial, centrally stipitate basidiomata with circular to flabelliform pilei, undulating margins, and sulphur-yellow to clay-buff upper surface when fresh, irregular to angular pores, monomitic hyphal system with generative hyphae bearing simple septa, and broadly ellipsoid basidiospores, measuring 5.5–7.4 × 5–6.7 μm, amyloid and acyanophilous. This study provides an illustrated description of the new species, molecular phylogeny, and comparisons with morphologically similar species.