powdery mildew
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- any of an order (Erysiphales) of ascomycetous fungi that are parasites on the surfaces of higher plants and produce closed fruiting bodies in a powdery mass
- a plant disease caused by a powdery mildew
See powdery mildew in American Heritage Dictionary 4
noun- Any of various fungi, especially of the family Erysiphaceae, that produce powdery conidia on the host surface.
- A plant disease caused by any of these fungi.
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