Cucumber mosaic virus on petunia. Photo by: Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org.

Septoria leafspot on Rudbeckia. Photo borrowed from: http://www.ppdl.org/dd/id/septoria-rudbeckia.html and taken by Karen Rane, Plant Disease Diagnostician.

Septoria leafspot on Rudbeckia. Photo borrowed from: http://www.ppdl.org/dd/id/septoria-rudbeckia.html and taken by Karen Rane, Plant Disease Diagnostician.