New and noteworthy records of Myriolecis (Lecanoraceae, lichenized Ascomycota) in the arid regions of northwestern China

Myriolecis represents one of the richest genera in species diversity within Lecanoraceae. In this study, approximately 700 specimens collected from high-altitude, temperate continental arid-climate regions in northwestern China, including the Kunlun Mountains, the southern Tianshan Mountains, and the Karakoram Range, were examined. A total of six species were identified, among which three are described as new to science: Myriolecis convexa, M. incisa, and M. kunlunica; and three are newly recorded in China: M. fugiens, M. mons-nivis, and M. wetmorei.

All species were identified based on morphological, anatomical, and molecular data. Phylogenetic analyses using internal transcribed spacer (ITS) and mitochondrial small subunit (mtSSU) sequences confirm the placement of these species within Myriolecis and support the current species delimitations. Detailed morphological descriptions, illustrations, distribution data, chemical information, and ecological notes are provided for each species, along with comparisons with morphologically similar and phylogenetically related species within the genus.

A dichotomous key to 22 species of Myriolecis from China is presented.