Erysiphe knautiae

Erysiphe knautiae is a powdery mildew which affects plants in the Scabious family, appearing as a powdery white substance particularly on both surfaces of the leaves. Microscopic examination is needed to separate this mildew from Podosphaera dipsacacearum.

Podosphaera dipsacacearum is similar but the conidia of Erysiphe knautiae haven't got fibrosin bodies in them, just the usual cell contents – these are present in the conidia of P. dipsacacearum

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.

Affects plants in the Scabious family.

When Scabious are in leaf.

It appears to be widespread in Britain

Rarely recorded in Leicestershire and Rutland.