Reevaluating Mycena section Amparoina (Mycenaceae, Agaricales) in the northwestern Iberian Peninsula and Macaronesia, with descriptions of four new species and a new European record

Mycena section Amparoina, with 52 described taxa worldwide is the third largest section of the genus Mycena and it is characterized by the small basidiomata, the presence of acanthocysts and often cherocytes that form the universal veil, and spinulose cheilocystidia and caulocystidia. In the present study we describe four new species namely M. atlantica sp. nov., M. eucalypticola sp. nov., M. melanovelis sp. nov. and M. viridivelata sp. nov., together with M. corynephora, collected in the northwestern of the Iberian Peninsula and some Macaronesian islands. Furthermore, M. biornata is a new record for the European mycobiota and has been recorded from different localities in Portugal and Spain. Sequences from the nuclear internal transcribed spacer (ITS) were generated to infer the relationships within M. sect. Amparoina using maximum likelihood and Bayesian inference. The phylogenetic evidence, along with the morphological features, supported the recognition of the four new species within the M. sect. Amparoina. In addition, the phylogenetic position of M. sect. Amparoina and its relationship with other sections of the genus Mycena are discussed. Detailed macro- and micromorphological descriptions, line-drawing illustrations, and photographs of the new species are provided.