Based on historic collections of liverworts and hornworts of the Tristan da Cunha group of islands in the South Atlantic Ocean, and heretofore-unstudied more recent large collections, the authors present information on 145 taxa occurring in the islands. This includes taxonomic and nomenclature remarks, including descriptions of new taxa; specimen citations; literature records; distributions; and ecology. Other features include a history of exploration, a description of the island group's phytosociology, and an assessment of the phytogeographic affinities of the Tristan-group liverworts and hornworts.
