DISEASE: Bunch disease
HOST: Walnut
Tree with advanced disease symptoms of branch and twig death.

Bunch disease | Walnut
DISEASE: Bunch disease
HOST: Walnut (Juglans microcarpa)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Crown gall
HOST: Aspen
Aspen with large, encrusted gall.

Crown gall | Aspen
DISEASE: Crown gall
HOST: Aspen (Populus sp.)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: S. Thomson
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