A novel, exclusively lichen-inhabiting lineage of hypocrealean fungi revealed in the <i>Sordariomycetes</i>

Lichen-inhabiting (lichenicolous) fungi comprise a considerable portion of the <i>Hypocreales</i> (<i>Sordariomycetes</i>), 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 <i>Hypocreales</i>. Through an order-wide phylogeny based on multiple loci, we unveiled a novel lineage within the <i>Hypocreales</i>, composed exclusively of lichenicolous species from genera such as <i>Ovicuculispora</i> and <i>Paranectria</i>, along with <i>Nectriopsis lichenophila</i> and <i>Nectria byssophila</i>-like taxa. Beyond the strong phylogenetic support, the clade is also characterized by its distinct morphology. Here it is introduced as a new family <i>Paranectriaceae</i> 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 (<i>Rossmaniella</i> and <i>Sphaeronectria</i>) and four new species (<i>Rossmaniella coenogonii</i>, <i>R. cryptica</i>, <i>R. filispora</i>, and <i>R. tylophori</i>). Additionally, we reinstated the genus <i>Ciliomyces</i>, with the type species <i>Ciliomyces oropensis</i>, from the synonyms of <i>Paranectria</i>. Our results also show that the genus <i>Neobaryopsis</i> is more closely related to the family <i>Calcarisporiaceae</i> than to the <i>Cordycepitaceae</i>, as originally described. A key to species determination within <i>Paranectriaceae</i> is provided. The present study suggests that neglected lichenicolous fungi are an important component that appears in <i>Hypocreales</i> several times during their evolution, and indicates that their considerable diversity can still be hidden. <b>Citation:</b> Darmostuk V, Etayo J, Rodriguez-Flakus P, Kukwa M, Pino-Bodas R, Pérez-Ortega S, Flakus A (2025). A novel, exclusively lichen-inhabiting lineage of hypocrealean fungi revealed in the <i>Sordariomycetes</i>. <i>Persoonia</i> <b>54</b>: 47-91. doi: 10.3114/persoonia.2025.54.02.