Heteroecism

Heteroecism, in fungi, or other parasites, is the passing different stages of development on distinct hosts. A striking instance is the corn-mildew (Puccinia yraminis), which at one stage is known as the cluster-cup of the barberry, formerly named AEcidium berberidis, whilst other stages, one once named Uredo, and the other and final one known as Puccinia, occur on wheat or some other grass.