DISEASE: Aster yellows
HOST: Aster
Foliar symptoms of chlorosis, malformation of leaves, and phyllody.

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Flowers with phyllody (left and center). Healthy flower (right).

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Bacterial blight
HOST: Lilac
Blighted twig with shriveled leaves and dark brown streaks on stem.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial blight
HOST: Lilac
Lilac with blighted twigs.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
DISEASE: Bacterial leaf spot
HOST: Laurel (California laurel)
Leaf with dark brown, angular spots.

Bacterial leaf spot | Laurel (California laurel)
DISEASE: Bacterial leaf spot
HOST: Laurel (California laurel) (Umbellularia californica)
PATHOGEN: Pseudomonas sp.
PATHOGEN SYNONYM: Pseudomonas lauracearum
SOURCE: W. Sinclair
DISEASE: Witches'-broom
HOST: Lilac
Lilac with broomlike symptoms and dead twigs.

Witches'-broom | Lilac
DISEASE: Witches'-broom
HOST: Lilac (Syringa josiflexa 'Royalty')
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: C. Hibben, W. Sinclair