Erioderma is a genus of lichenized fungi in the family Pannariaceae. They are commonly called mouse ears or felt lichens, and are small, pale brown to olive-brown foliose cyanolichens with a fuzzy upper surface that have the cyanobacteria Scytonema as their photobiont. Most species are found in the tropics of Central and South America, although three species are found in coastal regions of North America where they generally grow on mossy branches in humid sites. All North American species are rare, and two of them, Erioderma mollissimum and Erioderma pedicellatum, are listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Erioderma pedicellatum is also listed as critically endangered on the IUCN Red List of Threatened Species. Species of Erioderma c