Uromyces viciae-fabae var. viciae-fabae is a plant pathogen commonly known as Faba-bean rust. It is a leaf and stem rust of beans and causes partial defoliation, a reduction in photosynthetic leaf surface and a reduction in yield. This rust fungus occurs on both cultivated and wild plants of Vicia, Lathyrus, Pisum and Lens. It is autoecious, completing its life cycle on one plant host and macrocyclic, producing five types of spores during its life cycle.