A new species Boehmeria kamley N. Acharya & Yonek. and a new variety of B. densiflora Hook. & Arn. var. intermedia N. Acharya & Yonek. are described from the Himalaya. Status of B. penduliflora Wedd. ex D. G. Long and B. densiflora Hook. & Arn. are discussed and a new combination B. densiflora var. penduliflora (Wedd. ex D. G. Long) N. Acharya & Yonek. is proposed.

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A new orchid species, Dendrobium suzukii Yukawa, is described from Vietnam. It is easily distinguished from the closely related Dendrobium cruentum Rchb. f. by the following combination of characters : 1) much larger perianth lobes ; 2) a semiglobose callus on the basal part of the labellum ; 3) five keels on the labellum ; 4) undulate margins on the mid lobe of the labellum ; 5) a wider callus with cristate protuberances on the mid lobe of the labellum. Molecular phylogenetic analyses of the ITS (internal transcribed spacer) region of the 18S-26S nuclear ribosomal DNA also support a separate taxonomic status of the new species and its sister group relationship to D. cruentum.

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Raikoke is a small volcanic island in the Kuril Archipelago for which there has been no previously published botanical research or plant list. Although Tatewaki and Tokunaga collected on the island in 1928, no subsequent botanical investigations were made until the field work performed under the auspices of the International Kuril Island Project (IKIP) in 1996 and 2000. A first plant checklist, including the specimens collected in 1928, is presented here and includes 27 families, 53 genera, and 68 species for the island. Shrubs of Salix subreniformis and S. aquilonia are common on the volcanic ash slope, but Alnus maximowiczii and Sorbus sambucifolia are very rare. Pinus pumila was not found, which is surprising since it is common on other islands in the area. Shrub belts composed of Pinus or Alnus have not formed on the island, indicating that the island remains at an early stage of plant succession after the 1924 volcanic eruption. Establishment of Salix may be easier than that for Alnus or Pinus in the central Kuril Islands because of the more effective long distance seed dispersal in Salix, although the vegetative reproduction of survivors after the volcanic eruption cannot be ruled out. True ferns (Polypodiophyta) appear to be rare on Raikoke.

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Systematic position of Hymenophyllum rolandi-principis, or a monotypic genus Rosenstockia, has been traced by a combination of comparative morphology, cytogenetics, and molecular systematics. It is concluded that this filmy fern has a close relationship to H. dimidiatum in spite of its peculiar phenetic characters. Along with that, taxonomical characters of Hymenophyllum s. l. are preliminarily re-evaluated.

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Members of the Podostemaceae grow submerged in rapidly flowing water in the rainy season, but are exposed and flower and eventually die in the dry season. Pollen-ovule ratios (P/O) of 20 species in 15 genera in the family were calculated and pollination in some species was observed. We observed that autogamous species have low values of log P/O, while allogamous species have high values. We therefore conclude that species with values of log P/O higher than 2.5 are allogamous, while those with a ratio lower than 2.0 are autogamous. The species of the subfamilies Weddellinoideae and Tristichoideae are inferred to be autogamous. The subfamily Podostemoideae consists of species with various pollination types ranging from allogamy to autogamy and cleistogamy. The ancestor of the family that invaded the specialized aquatic habitat may have been autogamous.

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We report for the first time a diploid cytotype (2n-54) in the Thelypteris angustifrons complex from Okinawa Isl., the Ryukyus, although a hexaploid (2n 162, x=27) or a hyperhexaploid (2n-164) has been reported from Japan (Kyushu and Honshu) and a diploid (n=31) from Taiwan. The hexaploid is also found in Amami-oshima Isl. and more northern Japan. In addition, a triploid (2n=81) and a hypotetraploid (2n-107) are found in Amami-oshima Isl. and may be hybrids, because of irregular spore morphology. The spores of the diploids have less developed perispore and are smaller than those of the hexaploids. A variation in spore size of herbarium specimens examined shows that putative diploids occur only on Okinawa and Yakabi Isls. The diploid cytotype seems to be restricted to Okinawa and its neighboring area and also probably to Taiwan, while the hexaploid seems to be widely distributed from Taiwan north to warm temperate regions of Japan. From differences in chromosome number and spore and leaf morphologies, the diploid cytotype is regarded as T. miyagii, a species independent of the hexaploid T. angustifrons. The two related species, T. glanduligera and T. cystopteroides, were compared to the complex.

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A review of the floristic affinity of moss floras of Japan, Taiwan and the Philippines is presented. The results show that as many as 50 genera of mosses in Japan do not disperse southward to Taiwan while there are only 28 genera from Taiwan not found in Japan. Japanese moss taxa not present in Taiwan are the arctic and boreal members whereas the Taiwan moss taxa not found in Japan are the Malesian, Himalayan and SW Chinese endemics. A comparison of the floristic affinity of the moss floras of the Philippines and Taiwan reveal the same uneven north/south exchange of moss taxa.57% of Philippine mosses are not found in Taiwan while a high 64% of Taiwan mosses are not found in the Philippines. The demarcation line between the Taiwan and the Philippine (Luzon) floras is shown to be a strong barrier and be renamed Merrill's Line. Climatic, biological and geological factors causing the differences in species composition and patterns of distribution among the moss floras of Japan, Taiwan and the Philippines are outlined. Lastly, the reported oceanic distribution pattern of mosses from Japan to Taiwan and northern Philippines is also discussed.

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Anthecological observations on two Japanese orchids, Cypripedium macranthos var. speciosum and Dactylorhiza aristata, were preliminarily carried out. The results suggested that nectarless flowers of C. macranthos var. speciosum and D. aristata are pollinated by small bees including Andrena ruficrus rabicrus and by queen bumblebees, respectively.

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