Disease: Black spot of rosePathogen: Diplocarpon rosaeHosts: Rose, Rosa spp.
Black spot of rose, caused by the fungus Diplocarpon rosae, is a common disease on rose bushes. This disease also causes yellowing and abscission of the leaves, and it can produce lesions on the canes. Minimize disease by watering the soil surface to keep the leaves dry. Clean up diseased leaves and prune diseased canes.
Image is from the APSnet Herbaceous Ornamentals and Roses CD-Image 460: Black spot of rose.