DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial brown spot
HOST: Mallotus
Leaf with small, rustylike lesions.

Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Goto
DISEASE: Bacterial brown spot
HOST: Mallotus
Leaf with tiny, light brown spots surrounded by chlorotic zones.

Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Kobayashi, M. Goto
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Blighted leaves and stems.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Poinsettia with diseased stem. Woody stems may have a yellowed cortex and dark vascular tissues. The stem tip may curve with deformed terminal leaves.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Leaves with small, dark spots, an early stage of disease.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: A. Alvarez
DISEASE: Bacterial leaf spot
HOST: Mallotus
Leaf with dark and water-soaked lesions along veins.

Bacterial leaf spot | Mallotus
DISEASE: Bacterial leaf spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Erwinia mallotivora
SOURCE: M. Kobayashi, M. Goto
DISEASE: Bacterial leaf spot
HOST: Mallotus
Leaves with water-soaking, and one also with dark spots surrounded by chlorotic tissues.

Bacterial leaf spot | Mallotus
DISEASE: Bacterial leaf spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Erwinia mallotivora
SOURCE: M. Kobayashi, M. Goto
DISEASE: Bacterial leaf spot
HOST: Poinsettia
Leaves with reddish brown blighted areas and spots. Severely spotted leaves turn yellow and dehisce.

Bacterial leaf spot | Poinsettia
DISEASE: Bacterial leaf spot
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: A. Chase