Molecular circumscription and relationships of selected Gondwanan species of Haplomitrium (Calobryales, Haplomitriopsida, Hepaticophytina)
Stech, Michael; Frey, Wolfgang
CpDNA trnLUAA intron sequences of five Haplomitrium species (H. blumii, H. chilensis, H. gibbsiae, H. hookeri, and H. mnioides) and 42 species of Jungermanniopsida are compared. Maximum parsimony and maximum likelihood calculations of partial trnL intron sequences clearly resolve the genus Haplomitrium as monophyletic with high bootstrap support. Haplomitrium is separated from the Jungermanniopsida in trees with species of the Treubiopsida as outgroup representatives, which therefore support the recognition of a class Haplomitriopsida, as proposed earlier based on non-molecular characters. Close relationships between the Southern Hemispheric species Haplomitrium blumii and H. mnioides of subg. Calobryum and between H. gibbsiae and H. chilensis of subg. Haplomitrium sect. Archibryum are indicated, while the Northern Hemispheric H. hookeri (subg. Haplomitrium sect. Haplomitrium) is separated from both clades. According to the morphological, ecological and molecular divergence, Haplomitrium gibbsiae and H. chilensis, which were either regarded as a palaeoaustral species pair or as conspecific, to some extent underwent divergent evolution after the disruption of the palaeoaustral region and might at least be regarded as subspecies of a single species.