Abstract
The liverworts of Île Amsterdam are surveyed. On the basis of historical collections and specimens collected on the island in 2006 and 2007 some 29 species and one variety belonging to 18 families have been recorded.
This means that in comparison with the last survey of the island's hepatics, in 2002, the number of taxa has been nearly doubled. Of these, eight taxa are recorded for the first time from the island, namely Kurzia capillaris (Sw.) Grolle subsp. stephanii (Renauld ex Steph.) Pócs, Adelanthus lindenbergianus (Lehm.) Mitt., Syzygiella colorata (Lehm.) K.Feldberg, Vána, Hentschel et J.Heinrichs, S. sonderi (Gottsche) K.Feldberg, Vána, Hentschel et J.Heinrichs, Cephaloziella varians (Gottsche) Steph., Anastrophyllum auritum (Lehm.) Steph., Andrewsianthus marionensis (S.W.Arnell) Grolle and Heterogemma patagonica (Herzog et Grolle) L.Söderstr. et Vána, whilst Aneura subcanaliculata R.M.Schust. is excluded from the island's hepatic flora.
Two taxa, Kurzia capillaris subsp. stephanii and Gymnomitrion subintegrum (S.W.Arnell) Vána, are illustrated, and maps of global distribution are presented for Plagiochila minutula (Hook.f. et Taylor) Gottsche, Lindenb. et Nees, Andrewsianthus marionensis, Heterogemma patagonica, Mnioloma fuscum and Gymnomitrion subintegrum. The liverwort flora is distinctly south-temperate to tropical and these two main distribution patterns consist of 12 and eight species, respectively.
The subantarctic element is represented by only three species, two species are endemic or near-endemic and five bipolar. Two names, Riccardia insularis Schiffn. and R. novo-amstelodamensis Schiffn., are lectotypified.