Numerous, large brown leaf spots with light-colored centers and darker brown borders.

Two leaves showing symptoms of leaf spots on upper and lower surfaces.

Close-up of leaf spots.

A single leaf spot with small, black spore-producing bodies ("pycnidia") with white ooze containing spores.

Black spore-producing bodies ("pycnidia") under dark-field observation.

Black spore-producing bodies ("pycnidia") with spores oozing out under dark-field observation.

Spores oozing from infected tissue under dark-field observation.

Conidia of a species of the fungus Phyllosticta.

Conidia of a species of the fungus Phyllosticta.