DISEASE: Bacterial leaf spot
HOST: Snapdragon
Leaves with large necrotic areas with brownish centers and purplish margins. Lesions are slightly sunken.

Bacterial leaf spot | Snapdragon
DISEASE: Bacterial leaf spot
HOST: Snapdragon (Antirrhinum majus)
PATHOGEN: Pseudomonas syringae pv. antirrhini
SOURCE: R. Raabe
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: Elm yellows
HOST: Elm
Elm yellows is characterized by witches'-brooms and stunting. Some cultivars have both yellow and reddish foliar discoloration.

Elm yellows | Elm
DISEASE: Elm yellows
HOST: Elm (Ulmus parvifolia)
PATHOGEN: 'Candidatus Phytoplasma ulmi'
PATHOGEN SYNONYM: Phytoplasma Elm yellows group
SOURCE: W. Sinclair