Taxonomic revision of Marasmius Fr. and Marasmiaceae Roze ex Kühner based on multigene phylogenetics and morphological evidence

Many taxonomic and systematic rearrangements were proposed to Marasmius Fr. since its original concept in 1835, and since 1980 when it became the type of Marasmiaceae. These were based on morphological and/or more recently molecular phylogenetic studies. This study conducted a comprehensive taxonomic and systematic evaluation of Marasmius that benefits the whole family, implementing multilocus (SSU, LSU, ITS, rpb2 and ef1-α) phylogenetic analyses integrated with morphological and other features. The resulting trees support (1) a Marasmiaceae clade-based circumscription within Marasmiineae, (2) a Marasmius clade-based circumscription within Marasmiaceae, and (3) a subgenus-section-subsection-series system. Two subgenera are proposed: Globulares and Marasmius. Marasmius auton. subgen. includes Crinis-eques sect. nov., sect. Marasmius, Sanguirotales sect. nov., Variabilispori sect. nov., and Sicciformes sect. nov., while Globulares subg. nov. groups sect. Globulares and sect. Sicci. Four subsections are proposed in sect. Globulares and three in sect. Marasmius and sect. Sicciformes. Seventeen series were defined in sect. Globulares and three in sect. Sicci. Selected traits were assessed for their phylogenetic signals within Marasmius, providing a robust framework for a natural system. Based on this analysis, Marasmiaceae includes Chaetocalathus, Crinipellis, Marasmius and Moniliophthora/Paramarasmius, and Campanellaceae fam. nov. includes Brunneocorticium, Campanella/Tetrapyrgos, Neocampanella, and Marasmiellus sect. Candidi. New species, names, combinations and epitypes are also proposed.