DISEASE: Aster yellows
HOST: Marigold
Infected plant (left) with yellowing and stunting.

Aster yellows | Marigold
DISEASE: Aster yellows
HOST: Marigold (Tagetes erecta)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: M. Shurtleff
DISEASE: Bacterial leaf spot
HOST: Larkspur
Infected leaflets with many purplish spots with necrotic centers.

Bacterial leaf spot | Larkspur
DISEASE: Bacterial leaf spot
HOST: Larkspur (Delphinium sp.)
PATHOGEN: Pseudomonas syringae pv. delphinii
SOURCE: R. Raabe
DISEASE: Bacterial leaf spot
HOST: Pothos
Leaf with black necrotic tissues with concentric rings of light and dark tissues.

Bacterial leaf spot | Pothos
DISEASE: Bacterial leaf spot
HOST: Pothos (Epipremnum pinnatum)
PATHOGEN: Pseudomonas cichorii
SOURCE: APS
DISEASE: Bacterial wilt
HOST: Pothos
Pothos with infected stem and petioles.

Bacterial wilt | Pothos
DISEASE: Bacterial wilt
HOST: Pothos (Epipremnum aureum)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: D. Norman
DISEASE: Bacterial wilt
HOST: Pothos
Plant with severely infected leaves and stems.

Bacterial wilt | Pothos
DISEASE: Bacterial wilt
HOST: Pothos (Epipremnum aureum)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: D. Norman
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: Pseudomonas leaf spot
HOST: Marigold
Marigolds with yellow apical chlorosis attributed to toxin production by the pathogen.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin
DISEASE: Pseudomonas leaf spot
HOST: Marigold
Chlorotic leaves with total loss of chlorophyll. Disease is also known as toxic chlorosis.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin