DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Bacterial leaf spot
HOST: Hydrangea (Oak-leaf)
Leaf with individual brown necrotic lesions and coalesced lesions that formed large necrotic areas. The disease is caused by an unclassified xanthomonad.

Bacterial leaf spot | Hydrangea (Oak-leaf)
DISEASE: Bacterial leaf spot
HOST: Hydrangea (Oak-leaf) (Hydrangea quercifolia)
PATHOGEN: Xanthomonas campestris
SOURCE: W. Uddin, W. Sinclair
DISEASE: Bacterial leaf spot
HOST: Magnolia
Leaf with black, angular spots.

Bacterial leaf spot | Magnolia
DISEASE: Bacterial leaf spot
HOST: Magnolia (Magnolia soulangiana)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raabe