Inter- and infraspecific relationships in the Gondwanan liverwort genus Hymenophyton (Hymenophytaceae, Hepaticophytina). Studies in austral temperate rain forest bryophytes 23

Inter- and infraspecific relationships in Hymenophyton Dumort. were studied by sequencing of the cpDNA trnTUGU-trnLUAA 5′exon intergenic spacer, trnLUAA 5′exon and trnLUAA intron and nrDNA internal transcribed spacer 2 (ITS2), and by morphological examination of representative specimens. Based on the molecular data, four taxa were recognised, comprising (i) Australasian H.�flabellatum (Labill.) Dumort. ex Trevis., (ii) Chilean specimens, (iii) New Zealand H.�leptopodum (Hook.f. & Taylor) A.Evans samples and (iv) a Tasmanian H. leptopodum specimen, respectively. The former three clades are supported by high bootstrap values, while the affinities of the latter specimen remain ambiguous in the calculated trnT-trnL and ITS2 trees. The observed sequence divergence supports the existence of a distinct Hymenophyton taxon in southern South America, delimitated from H. flabellatum and H. leptopodum on species level: H.�pedicellatum Steph. This reinstated species is described in detail; differentiating morphological and molecular characters are presented. Hymenophyton taxa have a basically palaeoaustral distribution pattern. Biogeography, dispersal biology and phylogeography of the taxa are discussed.