Uncinula macrospora is a

plant pathogen Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...

that causes a

powdery mildew Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of ascomycete fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, as ...

disease of certain North American trees. Its hosts include various elms (''

Ulmus Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of Nor ...

'' spp.), hackberries (''

Celtis ''Celtis'' is a genus of about 60–70 species of deciduous trees, commonly known as hackberries or nettle trees, widespread in warm temperate regions of the Northern Hemisphere. The genus is part of the extended hemp family (Cannabaceae). De ...

'' spp.), and American hop hornbeam ''

Ostrya virginiana ''Ostrya virginiana'', the American hophornbeam, is a species of ''Ostrya'' native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Populations ...

''.

References

External links

Index Fungorum

USDA ARS Fungal Database
Fungal tree pathogens and diseases Erysiphales Fungi described in 1872 Taxa named by Charles Horton Peck {{fungus-tree-disease-stub