PHYLOGENETIC-RELATIONSHIPS IN THE MARCHANTIALES (HEPATICAE) - APPARENT INCONGRUENCE BETWEEN MORPHOLOGICAL AND MOLECULAR-DATA

A cladistic analysis of the order Marchantiales based on morphological characters (43 characters) did not agree with the classification in c urrent use. Molecular sequences of nuclear-encoded 26S rRNA genes of s even species of the order and two out-groups (1254-1299 bp) were analy sed to solve this contradiction. Results between morphologial and sequ ence data are conflicting. The combination of the two data sets shows that a weighting of the morphological data corresponding to equal cont ributions of the two sets resolves contradiction, We demonstrate that the structure of two data sets can be compatible even if the resultant trees are incongruent. Addition of a few compatible data (for instanc e, via character weighting) can result in congruent trees. The taxonom ic incongruence we observed could illustrate a case of two limited mol ecular sampling.