Mahonia Rust - Cumminsiella mirabilissima

The rust fungus Cumminsiella mirabilissima affects the leaves of Berberis repens, Mahonia aquifolium and Mahonia japonica usually producing numerous small red spots on the upper leaf surface with brown uredinia beneath. Aecia are uncommon.

Unless identified by a recognised expert, a photo is required. If the photo doesn't show the key ID features then in the comments box describe the size and identifying characters you have observed.

Where the host plants occur.

When the host plants are in leaf, most often towards autumn.

Oligophagous.

Widespread in much of Britain.

Status in Leicestershire and Rutland not known.