Chrysosplenium fauriae (in Series Macrostemon) with two varieties, var. fauriae and var. kiotense, is revised on the basis of morphology of flowers, capsules and seeds, cytology and geographical distribution. Some distinct morphological gaps are recognized between these varieties, and the existence of genetic isolation between them is also suggested from their sympatric occurrence. Variety kiotense is re-evaluated as a distinct species. A new species, C. nagasei, distributed mainly in central Gifu Prefecture and along the Ibuki-Suzuka Mountain Range is recognized in the C. fauriae group from the morphological and distributional evidence. Two varieties, var. luteoflorum and var. porphyranthes, are described on differences in flower colour and size. A brownish flowered form of C. fauriae found around Mt. Hyonosen (Hyogo and Tottori prefectures) is named f. ferruginiflorum.

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Morphological difference of floral characters, relation between relative age of plants and number of flowers/stem and variation patterns of the number of flowers/stem were studied in diploid, triploid and tetraploid plants of Japanese Adonis amurensis (Ranunculaceae). According to the degree of correlation between euploid change in basic number and observed values, floral characters were classified into three groups : (1) sepal shape, abaxial color of sepals, length and number of sepals, which were distinctly different between diploids and tetraploids, belonged to the first group, (2) the second group consisted of the characters like filament length, ratio of width to length of petals, petal width, abaxial color of petals, presence of incision along the apical margin of the sepals and petals and petal shape, which were different between diploids and tetraploids, and (3) lastly, such characters as number of petals, sepal width, petal length and ratio of width to length of sepals, which had low correlations with euploid change in chromosome number, were included in the third group. There was no relation between relative age of plants and number of flowers/stem in both diploid and tetraploid plants of Japanese Adonis. The tendency that tetraploids had mostly one to two flowers/stem and diploids possessed most frequently two to four flowers/stem was recognized. However, in diploid populations plants with only one flower/stem were observed at a frequency of 10-20% and in tetraploid populations plants with three and more flowers/stem were found at a frequency of 10% or more. Triploids were closer to diploids than to tetraploids in characters like presence of incision along the apical margin of both sepals and petals and number of flowers/stem, but they were more like tetraploids in sepal length, sepal shape, number of sepals, abaxial color of sepals, petal width, petal shape and number of pistils.

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Sexual dimorphism in Arenaria merckioides var.chokaiensis was investigated from morphological and reproductive points of view. The variety was found to be gynodioecious with hermaphrodite and female plants occurring in natural populations. Hermaphrodite flowers are characterized by their larger petals, longer filaments and larger anthers that contain viable pollen grains, and protandrous flowering habit. Female flowers, on the other hand, have smaller petals, larger stigmas and abortive anthers that contain no pollen grains. In addition, the stigmas of the female flowers mature earlier than stigmas in hermaphrodite flowers. The larger stigmas appear to increase the likelihood of pollen trapping in female flowers.

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The flower morphology and pollination biology of Monochoria korsakowii were studied in natural and transplanted populations. The plant has somatic enantiostyly, i.e., each plant bears two morphs of flowers, left- and right-handed flowers, witla the style deflection to the left and right, respectively. The enantiostyly is accompanied by a stamen dimorphism : each flower has five small and one large stamens, the large anther and the stigma are symmetrical with respect to the median plane of the flower. The major pollinators observed were Apis cerana japonica, Xylocopa circumvolans and Bombus spp. The large anther of a flower morph touches the same position of bee's abdomen as the style of the other morph, thereby apparently facilitating intermorph pollination. However, since the enantiostyly is somatic, this seems to lead to cross-pollination only when flowers of only one morph, by chance, are open on an individual. The flower was found to be self-compatible and capable of setting seed even in the absence of pollinators. It was the small stamen that contributed the autogamy.

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Architecture of the clonal growth was examined in Japonolirion osense Nakai, a vulnerable serpentine relict of Japan. Underground rhizomes with annual increments extending to 90 mm persist for many years ; in some to 24 years at least. By this vegetative rhizomatous spread a clonal plant occupies an extensive horizontal space over 30 cm in diameter. The rhizome system is sympodial, each unit ending in an erect leafy shoot whose leaves grow only for one season. Some leafy shoots with decayed leaves at the base bear terminal flowering scapes the succeeding year. The rhizome architecture is composed of a branched (multiple rhizomes elongated from each aerial shoot) and an unbranched (a single elongated rhizome) component. The branched component often includes long annual rhizomes and the scape-bearing shoots ; the unbranched component is formed by accumulated short annual rhizomes. A leafy shoot is adjacent to each scape-bearing shoot. The clonal growth pattern of Japonolirion permits an efficient method of vigorous vegetative extension on the unstable sandy serpentine slopes.

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The word "rheophytic mosses" applies to species which mainly, but not exclusively, inhabit the periodically flooded zones of rivers and streams. Though van Steenis did not refer to rheophytic mosses intensively, more than 130 moss species belonging to 31 families and 62 genera have been reported worldwide by various authors. The adaptive features of the morphology and physiology of rheophytic mosses are discussed in this article, especially their preference in habitat. Rheophytic mosses have certain morphologies that appear adaptive for a rheophytic environment, some of which differ from those of rheophytes of vascular plants. For example, mosses almost never have linear leaves, which are characteristic of the latter. In contrast, shoots of rheophytic mosses are terete or complanate and appear adapted to lessen water resistance. In addition, leaves of rheophytic mosses have obtuse apices, which causes the terete appearance of the shoots in wet conditions. The obtuse leaf apices might be related to the laminar cells of the leaf apex being shorter than those of the median part of the leaves. Another characteristic is the multi-layered leaf margins, particularly found in members of the Neckeraceae. They would give the leaves mechanical strength against damage caused by water. Since rheophytic mosses do not have thin-walled laminal cells that are characteristic of aquatic mosses, we concluded that rheophytic mosses are derived not from species inhabiting stable water but directly from the terrestrial species. We categorized the rheophytic mosses into three groups, each of which is inferred to have been derived from different "mother" groups of land species. Members of the three groups are as follows ; (1) epiphytic species totally restricted to the upper rheophytic zones where prolonged dessication occurs repeatedly ; (2) terrestrial species growing in permanently wet, lower rheophytic zones ; (3) saxicolous species inhabiting open and mostly dry places, such as on boulders in sunny riverbeds. The members of the first group are derived from land species growing on branches or trunks of shrubs and trees in forests (e.g., Cryphaeaceae, Brachytheciaceae); the second from species of forest floors (e.g., Neckeraceae, Thamnobryaceae); and the last from species inhabiting much drier places (Pottiaceae, Grimmiaceae). Since these three groups have different characteristics in morphological adaptation to rheophtytic environments, they should be treated separately whenever we study their speciation from land species.

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