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 blight
HOST: Spathiphyllum
Progression of disease severity on leaves from right to left.

Bacterial blight | Spathiphyllum
DISEASE: Bacterial blight
HOST: Spathiphyllum (Spathiphyllum sp.)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Viola (Horned violet)
The disease causes distortion and overgrowth of axillary buds.

Bacterial fasciation (Leafy gall) | Viola (Horned violet)
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Viola (Horned violet) (Viola cornuta)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Putnam