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: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.

Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.

Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial black leaf spot
HOST: Clover
White clover with brown necrotic spots.

Bacterial black leaf spot | Clover
DISEASE: Bacterial black leaf spot
HOST: Clover (Trifolium repens)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: M. Goto
DISEASE: Bacterial black leaf spot
HOST: Clover
White clover leaves with brownish spots and some yellowing occurring at the margins.

Bacterial black leaf spot | Clover
DISEASE: Bacterial black leaf spot
HOST: Clover (Trifolium repens)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: R. Gitaitis
DISEASE: Bacterial blight
HOST: Gypsophila (Baby's breath)
Gypsophila (baby's breath) with light brown, marginal leaf lesions and distortion.

Bacterial blight | Gypsophila (Baby's breath)
DISEASE: Bacterial blight
HOST: Gypsophila (Baby's breath) (Gypsophila paniculata)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: A. Hayward
DISEASE: Bacterial leaf spot
HOST: Amaranth
Brown necrotic leaf spots surrounded by narrow, yellow halos.

Bacterial leaf spot | Amaranth
DISEASE: Bacterial leaf spot
HOST: Amaranth (Amaranthus cruentus)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: M. Goto
DISEASE: Bacterial leaf spot
HOST: Bean
Leaves of velvet bean with necrotic lesions.

Bacterial leaf spot | Bean
DISEASE: Bacterial leaf spot
HOST: Bean (Mucuna pruriens var. utilis)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf spot
HOST: Bougainvillea
Bougainvillea with reddish brown, angular, vein-delimited spots and leaf distortion.

Bacterial leaf spot | Bougainvillea
DISEASE: Bacterial leaf spot
HOST: Bougainvillea (Bougainvillea sp.)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: A. Hayward