Morphological Diversity and Preliminary DNA Barcoding of Xylaria (Xylariales) from Estación Científica San Francisco, Including Xylaria aenea as a New Record for Ecuador

The genus <i>Xylaria</i> comprises numerous species, particularly prevalent in tropical ecosystems such as those of Ecuador. Despite its ecological importance, the taxonomy of the genus remains challenging, and much of its diversity in the Neotropics remains under-documented. This study provides a preliminary characterization of the <i>Xylaria</i> diversity at the Estación Científica San Francisco, an Andean biodiversity hotspot in Southern Ecuador. Through an integrated approach including detailed macro- and micro-morphological descriptions and nuclear ribosomal DNA (nrDNA ITS and LSU) phylogenetic analyses, 20 <i>Xylaria</i> specimens were examined. As a result, ten species were recognized: <i>Xylaria adscendens</i>, <i>X.</i> cf. <i>anisopleura</i>, <i>X. apiculata</i>, <i>X. curta</i>, <i>X. enterogena</i>, <i>X. fissilis</i>, <i>X. globosa</i>, <i>X. aff. telfairii</i>, <i>X. tuberoides</i>, and <i>X. aenea</i>, the latter representing a new record for Ecuador. The phylogenetic analysis presented here serves as a preliminary systematic positioning of these specimens within the genus rather than a comprehensive global reconstruction. While these ribosomal markers provided preliminary insights into species relationships, partial incongruence with morphospecies highlights the evolutionary complexity of certain lineages and underscores the need for future multilocus studies. Furthermore, four additional phylotypes found in their anamorphic state are documented, suggesting that local diversity exceeds current records. By providing detailed morphological documentation supported by preliminary barcode data from a poorly sampled region, this study contributes vital information to the global understanding of <i>Xylaria</i> and underscores the importance of Southern Ecuador as a reservoir of fungal diversity.