A brief survey of bryological studies in the Subantarctic, including Macrocoma tenue (Orthotrichaceae), a moss genus and species newly found in Îles Kerguelen

Studies on the bryophyte flora of the Southern Ocean islands and in the Antarctic are briefly reviewed and the current state of knowledge of the moss flora of Îles Kerguelen is discussed. Macrocoma tenue (Hook. & Grev.) Vitt is recorded from the Îles Kerguelen archipelago and this constitutes the first record of the genus Macrocoma (Müll. Hal.) Grout from the Subantarctic. The local plants of the species are characterized and illustrated and their ecology is discussed. Global distribution of M. tenue is reviewed and mapped. It is suggested that the type subspecies of M. tenue is a Gondwanan relictual taxon, which could have evolved on this supercontinent prior to its break-up and, subsequently, it reached Îles Kerguelen where it survived during the Pleistocene glacial epoch.