Recognition of Mycena sect. Amparoina sect. nov. (Mycenaceae, Agaricales), including four new species and revision of the limits of sect. Sacchariferae

Phylogenetic reconstruction revealed that Mycena stirps Amparoina, which is traditionally classified in sect. Sacchariferae, should be treated at section level. Section Amparoina is characterised by the presence or absence of cherocytes, the presence of acanthocysts and spinulose caulocystidia. Eight species referred to Mycena sect. Amparoina sect. nov. are recognised in China. Of these taxa, four new species classified in the new section are formally described: M. bicystidiata sp. nov., M. griseotincta sp. nov., M. hygrophoroides sp. nov. and M. miscanthi sp. nov. The new species are characterised by the absence of both cherocytes and a basal disc, along with the presence of acanthocysts on the pileus, spinulose cheilocystidia and caulocystidia. Descriptions of the new species, accompanied by illustrations of morphological characters and comparisons with closely related taxa, are provided. A multi-locus analysis utilising the ITS + nLSU + SSU regions was carried out using maximum likelihood and Bayesian Inference. A key to the 12 species of sect. Amparoina sect. nov. and sect. Sacchariferae that are found in China is provided.