A critical revision of the powdery mildew fungi (Erysiphaceae, Ascomycota) of Ukraine: Erysiphe sect. Erysiphe

This is the second article in a series of critical revisions of the species composition of powdery mildew fungi (Erysiphaceae, Helotiales, Ascomycota) of Ukraine and their distribution within the country. The first article of the series dealt with the small genera Arthrocladiella and Blumeria, while here we consider species of the Erysiphe sect. Erysiphe. Representatives of the other two sections of this genus, Microsphaera and Uncinula, will be critically examined in further publications. In the present article, a list of 24 species of the section Erysiphe recorded in Ukraine, their distribution by regions of Ukraine, and a key for their identification are provided. The most common species frequently occurring in many regions of Ukraine are E. aquilegiae, E. convolvuli, E. cruciferarum, E. heraclei, E. pisi, and E. polygoni. Such species as E. buhrii, E. howeana, E. knautiae, E. limonii, E. lycopsidis, and E. urticae were recorded less often. Erysiphe betae, E. circaeae, E. lythri, E. macleayae, E. mayori, E. thesii, and E. ulmariae are relatively rare species that occurred infrequently in several regions. Erysiphe caricae, E. catalpae, E. caulicola, E. celosiae, and E. malvae are known each from one or a few localities only. A number of species are invasive fungi, most of them have been recorded in Ukraine relatively recently, within the last hundred years. These are E. betae, E. caricae, E. catalpae, E. celosiae, E. howeana, and E. macleayae.