A taxonomic revision of Gollania recognizes seventeen species including one new species (G. schensiana). Seven species and one variety of Gollania are treated as synonyms of other species, one species is synonymized to a species of Taxiphyllum, and another species is transferred to Ectropothecium. The intergeneric relationship is discussed, and the infrageneric relationship is evaluated by means of the numerical method. A key for identification of species is provided, and for each species synonymy, description, illustration, specimens examined, habitat, distribution, diagnostic characters, and notes are given.

  An SEM survey was conducted to assess the degree of correlation between traditional generic concepts in the Bryaceae and peristome structure, especially patterns of ornamentation on dorsal exostomial surfaces. The most common ornamentation pattern in the family is reticulate-papillose, found in most species of Bryum, Pohlia, Rhodobryum, Acidodontium, and Epipterygium. Other ornamentation types found in the Bryaceae include papillose, striate, and smooth. Preliminary data indicate that Brachymenium is characterized by a distinctive exostomial ornamentation pattern which may provide a basis for refining the limits of that genus. Peristomial formulae in the family range from 4: 2: (2-)4 to 4 : 2: 14.

  The 70 Frullania species (+1 subspecies, 9 varieties, and 3 formae) belonging to 9 subgenera are confirmed in China, among which 1 subgenus and 4 species are new to science, and 12 species are newly reported from China. A new name (nom. nov.) and 12 combinations are proposed and several species are reduced to synonyms of other species. This study reveals the Frullania flora of China, particularly Yunnan and the neighboring provinces, to be most highly differentiated, containing many phytogeographically interesting taxa, and may be regarded as a center of the Paleotropic Frullania flora.

  Unclear relationships among the genera of the Hylocomiaceae and Rhytidiaceae, as presented by Brotherus in Die natürlichen Pflanzenfamilien, have resulted in a variety of taxonomic treatments. Whereas Fleischer emphasized growth pattern when he created the families, later workers have put greater emphasis on paraphyllia and peristome structure.

  Similarity graph clustering was used to estimate phenetic relationships on the basis of 50 morphological characters describing 71 species that represent the study group and several related families. Loeskeobryum is more similar to Rhytidiadelphus than to Hylocomium or Hylocomiastrum. These four genera plus Neodolichomitra form a reasonably distinct cluster. Pleurozium, Rhytidiopsis, and Rhytidium are phenetically isolated, yet they show some similarity to this cluster. Cryptoneurum, Okamuraea, Ptychodium, and Rigodiadelphus [“Lesquereuxia”] show very little similarity to other genera of the study group.

  Phylogenetic relationships among the genera were explored using character compatibility and parsimony analyses. The most parsimonious phylogenetic hypotheses and the one supported by the most credible clique of compatible characters place many genera from the study group on a clade defined by a weft life form. Hypotheses of evolutionary relationship based on growth pattern, paraphyllia, and peristome structure are incompatible. Hypotheses based on growth pattern and paraphyllia suggest that Hylocomiastrum, Hylocomium, and Loeskeobryum form a monophyletic group, whereas hypotheses based on exostome ornamentation and perforation of endostome segments suggest that Hylocomium and Pleurozium form a monophyletic group that is part of a larger clade composed of these two genera plus Loeskeobryum and Rhytidiadelphus.

  The Hylocomiaceae are redefined as a monophyletic family of cool-temperate to subarctic, weftforming mosses. Twelve genera are included in the family: Hylocomiastrum, Hylocomium, Leptocladiella, Leptohymenium, Loeskeobryum, Macrothamnium, Neodolichomitra, Orontobryum, Pleurozium, Rhytidiadelphus, Rhytidiopsis, and Rhytidium. Rhytidiaceae is synonymous with Hylocomiaceae. The following genera, which at one time or another have been included in the Hylocomiaceae or Rhytidiaceae, are excluded from the family and assigned elsewhere: Cryptoneurum (Brachytheciaceae), Cyathothecium (Hypnaceae), Gollania (Hypnaceae), Macrothamniella (Hypnaceae), Okamuraea (Leucodontaceae), Ptychodium (Thuidiaceae), Rigodiadelphus (Leskeaceae), and Stenotheciopsis (Hypnaceae).

  An SEM study of ornamentation on the dorsal surfaces of exostome teeth in the diplolepideous order, Bryales, includes forty-five species in thirty-five genera. A core of families that are also similar gametophytically share a common ornamentation pattern. The base of the teeth have a reticulate ornamentation in which low or high, branched or simple papillae frequently occur on the reticulum. The upper parts of the teeth are variously ornamented but are not reticulate. Although this pattern of dorsal exostomial ornamentation is by far the most common in the Bryales, others, such as smooth, striate, or papillose occur occasionally in several families.

  Nine species of Macromitrium are recognized in Japan. Only M. reinwardtii Schwaegr. is monoicous, the others are dioicous. The eight species are dimorphic and produce dwarf males. Male dwarfness in anisosporous species is genetically determined, while dwarfness in isosporous ones seems to be regulated by phytohormones from female plants. Small spores of anisosporous Macromitria always produce the dwarf males. In contrast the male spores of isosporous Macromitria have the potential to develop into either normal or dwarf males. When single male spores of isosporous Macromitrium japonicum were cultured, they matured into the normal males. However, when the spores were sown singly on media with auxin (2, 4-D), dwarf males developed.

  The occurrence of perigonia, perichaetia, and sporophytes was ascertained in herbarium specimens of the five dioicous species (three anisosporous, two isosporous) of Macromitrium Brid. in Japan. Sporophytes are frequently observed in Japan in all five species. Different distributions of dwarf and normal males were found in the two isosporous species, M. gymnostomum Sull. et Lesq. and M. japonicum Dozy et Molk. The dwarf males of these species were widely distributed in Japan, while the normal males were scarce and restricted to low altitudes, and latitude on the Pacific Sea side.

  An experimental study was carried out to explain the restricted distribution of normal male plant of isosporous species of Macromitrium in Japan. At 10℃ bud formation occurred on the female protonemata, whereas none of the male protonemata produced buds in 160 days. At 10℃ gametophore production was also less frequent in protonemata originating from male leaves than from those originating from female leaves. Low temperature seems to be the main factor restricting the formation of normal male plants.