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 wilt
HOST: Carnation
Carnation stem with cankers and cracks. Yellow sticky bacterial slime is often seen.

Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: E. Hellmers, Royal Veterinary & Agricultural University
DISEASE: Bacterial wilt
HOST: Carnation
Severely diseased and withered plants.

Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: T. Saito, M. Goto
DISEASE: Bacterial wilt
HOST: Carnation
Sliced stem with discolored vascular bundles.

Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: T. Saito, M. Goto
DISEASE: Bacterial wilt
HOST: Carnation
Systemic infection caused cracking and necrosis of the stem.

Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: R. Raabe
DISEASE: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
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