A new and threatened species of Bondarzewia from the Brazilian cloud forests.

A new and threatened polypore species, Bondarzewia loguerciae , is described from the cloud forests of southern Brazil. It is characterized by single-pileate basidiomata that grow on dead branches and along living stems of standing trunks and present a context with dark lines and resinous tubes. When growing in axenic culture, this species also develops chlamydospores. We provide an illustrated morphological description and molecular analysis. Our specimens from Brazil form a monophyletic group among other species of the Southern Hemisphere. The conservation status of B. loguerciae is assessed and published as "Critically Endangered" based on the International Union for Conservation of Nature  (IUCN) criteria. Additionally, a key to the species is provided.