Puccinia pittieriana (syn. Gerwasia pittieriana) is a species of rust fungus. It is a plant pathogen which infects agricultural crops such as potato and tomato. Its common names include common potato rust and common potato and tomato rust. The fungal spores are borne on the wind and infect plants when the plant surface is moist and the average temperature is around 10°C. Symptoms appear in about two weeks and the lesions are largest by 20 to 25 days after infection by spores. Several potato cultivars are resistant to the rust.