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: Croton
Leaves with dry, irregularly shaped, brown necrotic areas.

Bacterial leaf spot | Croton
DISEASE: Bacterial leaf spot
HOST: Croton (Codiaeum variegatum)
PATHOGEN: Xanthomonas codiaei
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Turnip
Leaf with many tan, dry-appearing, angular spots.

Bacterial leaf spot | Turnip
DISEASE: Bacterial leaf spot
HOST: Turnip (Brassica rapa)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Campbell