The fungus attacks young tissues of new leaves, fruits, flowers, shoots and succulent twigs. The first symptoms are chlorotic specks which become, after a few days, pustules containing uredia producing yellow masses of spores. Pustules can coalesce and parts of the plant can be completely covered with pustules. After about 2-3 weeks, pustules dry and become necrotic. The disease can cause deformation of leaves, heavy defoliation of branches, dieback, stunted growth and even death. On fruits of guava (Psidium guava, Psidium spp.), Ruberry (Myrcia spp., Myrciaria spp.) and other native American hosts in the Myrtaceae, the lesions occur mostly on buds and young fruits that eventually rot as the rust matures.
This autoecious fungus has a macrocyclic life cycle, producing aecia, uredinia, telia and basidia. Uredia amphigenous, in groups on brownish or blackish spots up to 5 m