Erysiphe euonymi

The powdery mildew Erysiphe euonymi  can sometimes be observed as a white dusting on the leaves of Spindle and other Euonymus species.  On close examination the powdery (anamorph) stage may also have little black dots which contain the ascospores (Sexual stage ) - this is known as the holomorph state.

Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters.

Where Spindle and other Euonymus species are present.

When the host species are in leaf, particularly in late summer and the start of autumn.

Mainly found in the south of England and Wales.

Rare or under recorded in Leicestershire and Rutland.