Porpoloma aranzadii is a synonym of Mycena dura further notes in Mycena sect. Calodontes

Mycena sect. Calodontes is a taxonomically intricate group comprising phylospecies so far not recognizable using a morphological recognition approach. In this study we re-examine and sequence Iberian material of Porpoloma aranzadii, including the type specimen. The dextrinoid lamellar trama and mycelial hyphae in the type specimen, the latter covered with crystals, suggest a placement in Mycena sect. Calodontes. The type specimen of M. pura f. brunnea is also examined and sequenced. We constructed an ITS dataset representing all European phylospecies reported in previous studies, and we coded indel information. Our phylogenetic analyses recovered strongly supported clades for all the phylospecies and indel information provides additional resolution in phylospecies delimitation. Porpoloma aranzadii sequences are encompassed in the M. dura clade and their synonymy is proposed. Further information on the macroscopic variability of M. dura is obtained. Within sect. Calodontes, M. dura is characterized by the fascicled or caespitose basidiomata, a grassland habitat and sometimes the lack of any raphanoid odour. Its distribution is extended to the Iberian Peninsula. The sequence obtained from the type of M. pura f. brunnea nests in M. pura clade 9. The new combination M. brunnea is proposed to formally refer to this clade at species rank. Mycena brunnea appears to be characterized by a predominantly brown pileus, the absence of deep purple tones and a forest habitat. Mycena brunnea is also macroscopically reminiscent of M. dura, but the former differs mainly in a gregarious growth of basidiomata and a forest habitat.