DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum
Leaves with irregular necrotic lesions.

Bacterial leaf spot and canker | Sweetgum
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum (Liquidambar styraciflua)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: A. Bishop
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum
Stem canker of sweetgum.

Bacterial leaf spot and canker | Sweetgum
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum (Liquidambar styraciflua)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: A. Bishop
DISEASE: Larkspur virescence
HOST: Larkspur
Two diseased plants with stunted and small leaves, lack of flower coloration, and bunched flower buds. Healthy plant (left).

Larkspur virescence | Larkspur
DISEASE: Larkspur virescence
HOST: Larkspur (Delphinium sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
DISEASE: Wildfire (Angular leaf spot)
HOST: Tobacco
Characteristic symptoms are necrotic, brown spots with angular margins surrounded by distinct yellow halos. The halos are caused by the production of tabtoxin.

Wildfire (Angular leaf spot) | Tobacco
DISEASE: Wildfire (Angular leaf spot)
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: G. Lucas