Four new records of the powdery mildews in Inner Mongolia.
Four new record species of the powdery mildews in Inner Mongolia were reported in this paper. They are Erysiphe betulina on Betula platyphylla (Betulaceae), Erysiphe ulmi var. ulmi on Ulmus macrocarpa (Ulmaceae), Podosphaera mors-uvae on Ribes burejense (Grossulariaceae) and Sawadaea koelreuteriae on Koelreuteria paniculata (Sapindaceae). Their morphological descriptions and illustrations in details were provided in the paper. Betula platyphylla and Ribes burejense were new host plants of the powdery mildews to China. The examined specimens were deposited in the Mycological Herbarium of Chifeng University (CFSZ).