The taxonomy of powdery mildew on plant species has been reevaluated and two new species, previously hidden under other names, have been described. Morphological and genetic analyses showed that two previously recognized species should be considered as one. Analyzing genetic sequences from powdery mildew collections around the world revealed that two monophyletic groups are separate from all other species. The study emphasizes the unreliability of taxonomic conclusions based solely on morphological distinctions. Overall, the findings provide important insights into the taxonomy of powdery mildew, which could be important for agriculture and plant breeding.