A stem canker disease of aLimoniumhybrid ‘Chorus Magenta’ was identified at several sites throughout the North Island of New Zealand. First symptoms included leaves of diseased plants turning yellow, often on one side of the leaf blades. Cankers developed blue‐black discoloration, and dark fruiting bodies of a fungus were located below the epidermis of cankers on dying plants. APhomopsissp. was consistently isolated from diseased stem tissue. Pathogenicity was confirmed by inoculating healthy plants with the fungus in the greenhouse. The pathogen was recognised as a new species and namedPhomopsis limonii.This is the first report ofPhomopsisonLimonium.