Pleurocordyceps gen. nov. for a clade of fungi previously included in Polycephalomyces based on molecular phylogeny and morphology

Since the discovery of the Pleurocordyceps/ Polycephalomyces clade unaffiliated with the clades of Clavicipitaceae s. str., Ophiocordycipitaceae, and Cordycipitaceae of clavicipitaceous fungi, some taxa have been published and more fungal material relevant to the group have become available for further study. Here, a multigene phylogeny using nrSSU, nrLSU, tef1, rpb1, and rpb2 was constructed with some of the recently discovered additional taxa using maximum likelihood and Bayesian analyses (BI) to test and refine the current phylogenetic framework for Cordyceps s. lat. and other clavicipitaceous fungi. In addition to the well supported major Pleurocordyceps/Polycephalomyces clade revealed previously, another clade with newly added taxa referred to as Polycephalomyces formosus-like from Japan was found to be sister to the Pleurocordyceps/Polycephalomyces clade. Extensive investigation revealed that strains named P. formosus-like grouped in this new clade and do indeed represent the true P. formosus and that species previously included in the genus Polycephalomyces required a new generic name. Based on the phylogenetic analyses and morphological characteristics, including both sexual and asexual morphs when available, the new generic name Pleurocordyceps is introduced and relevant new combinations are made. A newly designated lectotype and a supporting epitype for P. formosus is selected and the circumscription of Polycephalomyces is discussed.

Automated summary

This study constructed a multigene phylogeny to test and refine the current phylogenetic framework of Cordyceps s. lat. and other clavicipitaceous fungi, revealing a new Pleurocordyceps/Polycephalomyces clade. A newly designated generic name Pleurocordyceps was introduced based on phylogenetic analyses and morphological characteristics, with relevant new combinations made. Additionally, a lectotype and an epitype for P. formosus were selected, and the circumscription of Polycephalomyces was discussed.