Three new species of Ochrolechia (Ochrolechiaceae, Pertusariales) from Guizhou Province, China

Based on morphological, chemical and phylogenetic analyses, three species of <i>Ochrolechia</i> collected from Guizhou, China, are described as new to science and named <i>Ochrolechia guizhouensis</i>, <i>O. kuankuoshuiensis</i> and <i>O. leigongshanensis</i>. Phylogenetic trees, based on ITS and mtSSU loci, were constructed using Maximum Likelihood analysis (ML) and Bayesian Inference (BI) methods. <i>Ochrolechia guizhouensis</i> and <i>O. akagiensis</i> are positioned close to each other in the phylogenetic tree. <i>Ochrolechia guizhouensis</i> is morphologically characterised by its apothecia which feature rugose to rosulate, epruinose discs resembling a floral structure. Chemically, the apothecia contain gyrophoric acid, lecanoric acid and lichesterinic acid, while the thallus contains only gyrophoric acid and lecanoric acid. Phylogenetic analysis reveals that <i>Ochrolechia kuankuoshuiensis</i> is closely related to <i>O. parellula</i> and is distinguished by its light yellow, epruinose, deeply rugose apothecial discs, the production of gyrophoric acid and lecanoric acid and the largest ascospores known in the genus. <i>Ochrolechia leigongshanensis</i> forms an isolated phylogenetic branch which is characterised by a soraliate thallus and apothecia with a ring of smooth, salmon-pink tissue on the inner margin. The discs are epruinose to lightly pruinose and plane. The thallus contains gyrophoric acid, lecanoric acid and a trace of atranorin, while the apothecia contain only gyrophoric acid and lecanoric acid. Additionally, <i>O. subrosella</i> and <i>O. longispora</i> were successfully sequenced for the first time and represent the first records from Guizhou Province. We found one specimen, which phylogenetically groups with <i>O. trochophora</i>, but is characterised by the presence of soralia, indicating that <i>O. trochophora</i> might be morphologically more variable than previously thought. Colour photographs are provided for all the above-mentioned species.