Family Melampsoraceae is a group of fungal pathogens commonly known as rust fungi. These fungi are known to cause disease in a variety of plants, including conifers, alders, birches, and willows. Alternative names for family Melampsoraceae include the rust fungi family, the Melampsorales family, and the Melampsoraceae order. These fungi are characterized by the presence of spores that produce rust-colored pustules on plant leaves, bark, and stems. The rust fungi family plays an important role in the ecosystem, as well as in agriculture and forestry, where they serve as both allies and pests.