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

摘要

Inter- and infraspecific relationships in Hymenophyton Dumort. were studied by sequencing of the cpDNA trnT(UGU)-trnL(UAA) 5' exon intergenic spacer, trnL(UAA) 5' exon and trnL(UAA) 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.