There are several asci per cleistothecium. The cleistothecia have appendages that may or may not be branched, but always have recurved tips. Uncinula commonly affects grapes, horsechestnuts, linden, elm, willow, and maple.
 
 

Representative Species

Uncinula necator

Causes powdery mildew disease of grape vines. This fungus severely threatend the wine industry in France but led to the discovery of sulfur-based fungicides to control the disease.