DISEASE: Larkspur virescence
HOST: Larkspur
Two diseased plants with stunted and small leaves, lack of flower coloration, and bunched flower buds. Healthy plant (left).

Larkspur virescence | Larkspur
DISEASE: Larkspur virescence
HOST: Larkspur (Delphinium sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
DISEASE: Rugose leaf curl
HOST: Clover
Two rugose, distorted white clover leaves and a healthy leaf. Rugose leaf curl is caused by an unidentified phloem-infecting bacterium.

Rugose leaf curl | Clover
DISEASE: Rugose leaf curl
HOST: Clover (Trifolium repens)
PATHOGEN: Phloem-infecting bacterium
SOURCE: D. Teakle
DISEASE: Walnut blight
HOST: Walnut
Typical symptoms of infected leaf and young nutlets. Infected young, growing leaves usually become malformed.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: M. Schroth
DISEASE: Walnut blight
HOST: Walnut
Tree with severely blighted foliage.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: M. Schroth
DISEASE: Walnut blight
HOST: Walnut
Nuts with side blight. Infections also are commonly found at stylar ends.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: B. Teviotdale
DISEASE: Walnut blight
HOST: Walnut
Nuts with decayed kernels.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: B. Teviotdale
DISEASE: Walnut blight
HOST: Walnut
Three catkins with different degrees of infection.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: M. Schroth