A revision of the genus Bazzania Gray (Lepidoziaceae, Marchantiophyta) in New Caledonia with a review of the type specimens

The genus Bazzania Gray (Lepidoziaceae, Marchantiophyta) was reviewed in several countries around New Caledonia, but the species of the local flora remain still imperfectly known and the oncoming survey of this flora often faces challenges in identifying new specimens. Some morphological characters used to differentiate the species are commented on, especially the insertion of the underleaves in relation to the ventral leaf bases. A review of types and reference specimens examined at G, PC and REN, together with about 250 recent vouchers collected mainly by the author allows characterization of 18 species based on morphological criteria and several taxonomic changes, mainly synonymies. Among the 18 species, seven are endemic: Bazzania bernieri (Steph.) Inoue & H.A.Mill., B. bescherellei Steph., B. consociata (Steph.) H.A.Mill., B. deplanchei (Gottsche ex Steph.) Jovet-Ast, B. incrassata (Steph.) N.Kitag., B. paucidens (Steph.) H.A.Mill. and B. quadratistipula H.A.Mill. Environmental conditions may have a strong impact on some morphological characters, so, to support species circumscriptions, further studies are needed that take account of ecological data and use macromolecular analysis. Several years ago, chemical investigations were initiated and could help to consolidate species delineation. A key to the New Caledonian species is provided and each species described and illustrated.