Sudden Oak Death and Associated Diseases Caused by <i>Phytophthora ramorum</i>

Fig. 9D. Infected rhododendron leaves have dark brown lesions. Necrosis is often concentrated along the midvein in leaves infected from a twig infection via the petiole. Leaves infected without prior twig infection can have leaf spots on any part of the leaf surface. 9D shows naturally infected leaves of the native rhododendron, R. macrophyllum, from southwestern Oregon.



Image from Plant Health Progress article:
Sudden Oak Death and Associated Diseases Caused by Phytophthora ramorum