Xanthomonas is a genus of bacterial plant pathogens. Species in the group demonstrate high specificity to different plant species. Many important Xanthomonas pathogens are split into groups called pathovars (abbreviation pv.). A pathovar is a bacterial strain or group of strains which share similar characteristics, (i.e. produce similar symptoms) but use different plants as hosts. Citrus Canker is caused by the pathovora Xanthomonas axonopodis pv. citri. As suggested by its name, it attacks Citrus plants, and can significantly impact the health of the plants it infects. Some of the crops commonly affected include lime, oranges, and grapefruit, which develop dark lesions on the fruits, stems and leaves.