Phylogenetics and morphological evolution of the Dicnemonaceae (mosses, order: Dicranales). Phylogenetics and evolution of the Hylocomiaceae (mosses, order: Hypnales)

Part I. The phylogeny of the Dicnemonaceae is reconstructed by cladistic analysis on ontogenetic and morphological data. The monophyly of this family is supported by uniquely derived structures of endospores and nematogenes. Based on the reconstructed phylogeny, the homology hypothesis of calyptra, struma, and leaf-rhizoids is tested by Patterson's tests of similarity, conjunction, and congruence. Hetreochronic evolutionary processes are invoked to explain the origins of evolutionary novelties and homoplasies. Tentative hypotheses of adaptation are proposed using Baum & Larson's (1991) phylogenetic methodology. In order to test these hypotheses more experimental studies on functional morphology of mosses are required.;Part II. The phylogeny of the Hylocomiaceae is reconstructed by cladistic analysis on morphological (ontogenetic) and molecular data. The variation of thirty-two morphological characters, including ontogenetic data of paraphyllia, central strands, and axillary hairs, is observed and polarized by outgroup comparisons. Cladistic analysis indicates that eight genera constitute the Hylocomiaceae, which is characterized by sympodial growth-form with a reversal to monopodial type in Orontobryum.;Internal spacers of nuclear ribosomal DNA and the noncoding rbcL-atpB spacer of the chloroplast are sequenced and aligned. Based on ITS sequence, seven genera are recognized in the Hylocomiaceae. The chloroplast spacer appears to be conservative and provides insufficient insight into the phylogeny of Hylocomiaceae. Nevertheless, the combined molecular data offers a complementary power to resolve the phylogeny at species as well as higher taxonomic levels.;The topology obtained from morphological data appears to be incongruent with those from molecular sequences. Templeton's nonparametric tests are used to test the taxonomic congruence and alternative taxonomic hypotheses. Although the tree obtained from the chloroplast spacer is not congruent with that of ITS sequences, when Templeton's test is conducted at generic level, the difference between two trees is not significant statistically. Moreover, the combined molecular data support an identical topology as does ITS sequences, which appear to be suboptimal tree to most data sets.;Thelia is indicated to be a genus of the Hylocomiaceae by the molecular systematics. It occupies an epiphytic adaptive zone. In contrast, other taxa in this family occupy the terrestrial adaptive zone. Based on the reconstructed phylogeny, the horn-like paraphyllia in the Hylocomiaceae appear to be derived from their common ancestor. The horn-like paraphyllia transformed into a peculiar type with lacinate margins, which occur in Thelia.