Day lily leaf streak. Photo from a pdf found at: http://www.doacs.state.fl.us/pi/enpp/pathology/pathcirc/pp376.pdf by R.M. Leahy & T.S. Schubert

Sclerotinia root rot on sunflower. Photo provided by: Howard F. Schwartz, Colorado State University, Bugwood.org

“Sclerotia” of Sclerotina stem rot inside infected stem. Photo provided by: Paul Bachi, University of Kentucky Research & Education Center, Bugwood.org

Powdery mildew on crape myrtle. Photo provided by: Robert Lambe, Virginia Polytechnic Institute and State University, Bugwood.org