A novel, exclusively lichen-inhabiting lineage of hypocrealean fungi revealed in the Sordariomycetes

Lichen-inhabiting (lichenicolous) fungi comprise a considerable portion of the Hypocreales (Sordariomycetes), their placement and phylogenetic relationships within the order remain largely unknown due to a lack of available molecular data. This study focuses mainly on tropical lichenicolous hypocrealean fungi which were neglected for a long time. Increasing knowledge of this fungal group is crucial to better understanding the complex evolutionary histories and trophic strategies of the Hypocreales. Through an order-wide phylogeny based on multiple loci, we unveiled a novel lineage within the Hypocreales, composed exclusively of lichenicolous species from genera such as Ovicuculispora and Paranectria, along with Nectriopsis lichenophila and Nectria byssophila-like taxa. Beyond the strong phylogenetic support, the clade is also characterized by its distinct morphology. Here it is introduced as a new family Paranectriaceae characterized by yellow to orange sessile ascomata, featuring a distinct tomentum, and by pigment in ascomata walls that do not change colour in KOH solution. The delimitation of interspecific and generic boundaries within the novel family was based on molecular, morphological and ecological data. As a result, we established nine species and five genera, including two genera new to science (Rossmaniella and Sphaeronectria) and four new species (Rossmaniella coenogonii, R. cryptica, R. filispora, and R. tylophori). Additionally, we reinstated the genus Ciliomyces, with the type species Ciliomyces oropensis, from the synonyms of Paranectria. Our results also show that the genus Neobaryopsis is more closely related to the family Calcarisporiaceae than to the Cordycepitaceae, as originally described. A key to species determination within Paranectriaceae is provided. The present study suggests that neglected lichenicolous fungi are an important component that appears in Hypocreales several times during their evolution, and indicates that their considerable diversity can still be hidden.