A genus of rust fungi, which form stalked, 2-celled teliospores. They parasitize (see parasitism) monocotyledonous (see monocotyledon) and dicotyledonous (see dicotyledon) plants throughout the world. Many species cause diseases of economic importance: for example, P. graminis causes black-stem rust of wheat, P. horiana causes chrysanthemum white rust, P. menthae causes mint rust, and P. striiformis causes yellow rust of wheat and other cereals. There are many species.
Subjects: Plant Sciences and Forestry.