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: Laurel (California laurel)
Leaf with dark brown, angular spots.

Bacterial leaf spot | Laurel (California laurel)
DISEASE: Bacterial leaf spot
HOST: Laurel (California laurel) (Umbellularia californica)
PATHOGEN: Pseudomonas sp.
PATHOGEN SYNONYM: Pseudomonas lauracearum
SOURCE: W. Sinclair