DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Bacterial fasciation (Shoot proliferation)
HOST: Campanula
Overproduction of new shoots and short, thickened, distorted stems.

Bacterial fasciation (Shoot proliferation) | Campanula
DISEASE: Bacterial fasciation (Shoot proliferation)
HOST: Campanula (Campanula sp.)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Putnam
DISEASE: Foamy canker
HOST: Koa
Foamy canker of koa is associated with bacteria and yeast. The causal agent has not been identified.

Foamy canker | Koa
DISEASE: Foamy canker
HOST: Koa (Acacia koa)
PATHOGEN: Causal agent unknown
SOURCE: H. Keyser