Powdery Mildews

Leaf Diseases of Hardwoods

Powdery Mildews

powdery mildew on leaves

Powdery mildew with the white mycelium covering the surface of the leaves.

powdery mildew

Powdery mildew on leaf surfaces produce large numbers of conidia.

conidia of powdery mildew

Illustration of conidia produced on leaf surface. Conidia, conidiophores and haustoria are shown.


Cleistothecia (also called Chasmothecia) observed in the class lab:


Cleistothecia with one acus. Note end of appendage with ornamentation. Podosphaera.

Powdery mildew

Cleistothecia with many asci and appendages with ornamentation. Microsphaera


Cleistothecia - appendages with bulbous base. Phyllactinia

powdery mildew on oak

Another view of Phyllactinia from the oak leaf taken during the lab by Kara 


Cleistothecia - appendages with curled ends. Uncinula

Cleistothecia Drawing

A drawing from the 1800's showing a few different types of appendages on cleistothecia