The genus is characterized by its dark chasmothecia which bear filamentous, hyaline appendages with hooked tips.

Braun and Takamatsu (2000) suggested that Uncinula should be considered a later synonym of Erysiphe; not all subsequent researchers have accepted their conclusions.

Erysiphe necator), attacks various species of grapes (Vitis spp.)

and can cause yield losses in European wine grapes.

Other Uncinula species attack a wide variety of dicotyledonous plants.