DISEASE: Apple proliferation
HOST: Apple
Enlarged stipules on leaf. Witches'-brooms, rosettes, and enlarged stipules are the most reliable symptoms for identification.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Granny Smith')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Bacterial blight
HOST: Poppy
The disease begins with water-soaked lesions that turn brown to black. They may be surrounded by a translucent ring. Buds, leaves, flowers, and pods are affected.

Bacterial blight | Poppy
DISEASE: Bacterial blight
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Xanthomonas campestris pv. papavericola
SOURCE: M. Daughtrey
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: Crown gall
HOST: Poppy
Crown gall of California poppy, a native wild flower.

Crown gall | Poppy
DISEASE: Crown gall
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Schroth
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