Phylogeny and taxonomy of Erysiphe pulchra (Erysiphales) and E. cornicola nom. nov.

Cornus spp. are commonly cultivated in parks or gardens as ornamental plants. Powdery mildew is one of the most important diseases of these plant species. Molecular phylogenetic analyses of the causal agent Erysiphe pulchra showed that this species is divided into two genetic groups, viz. one found on C. florida and C. kousa, and another one on C. controversa, both apart from each other. Combined with detailed morphological examinations, E. pulchra s. str. and E. cornicola nom. nov. are proposed for the respective fungal groups.