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: Verbena
Leaf with purple-brown necrotic spots.

Bacterial leaf spot | Verbena
DISEASE: Bacterial leaf spot
HOST: Verbena (Verbena sp.)
PATHOGEN: Pseudomonas sp.
SOURCE: R. Raabe