New records and a new species of Erysiphe (Erysiphaceae, Ascomycota) from Mexico

Mexico hosts a wide diversity of plant species, which is reflected in the high number of powdery mildew species present in the country. Nevertheless, many of them have not yet been detected and are often undescribed. The present work provides records of 13 species belonging to the genus Erysiphe (including sect. Erysiphe, sect. Microsphaera, and sect. Uncinula) from Mexico. In most cases, only asexual morphs have been found, which require molecular phylogenetic analyses based on ITS+28S rRNA sequences in addition to morphological examinations for accurate identifications. Five new reports: E. ampelopsidis, E. intermedia, E. peckii, E. rumicicola, and E. russellii and two new hosts for Mexico, viz., Casuarina equisetifolia (E. diffusa) and Lupinus elegans (E. intermedia), are amongst the new collections. The new species Erysiphe burserae, on Bursera kerberi and Bursera sp., is introduced, illustrated, and discussed.