A new species of the genus Didymoplexiella (Orchidaceae), D. cinnabarina, is described and illustrated. This saprophytic/mycoheterotrophic orchid was found in the Muller Range, Central Kalimantan, Indonesia. A combination of several characters, such as long, decurved stelidia, the absence of a column foot, a trilobed lip, and clear coloration, indicates that this species belongs to the genus Didymoplexiella. It is clearly distinct from other known species of Didymoplexiella in the vermilion-red coloration of the entire inflorescence and flowers, and the moderate size of its flowers. It most resembles D. kinabaluensis, which was collected from Menetendok Gorge, Kinabalu, Sabah, Borneo, but differs in color and lip morphology. This species is the eighth species of the genus reported so far.

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Borneo, being part of the centre of banana origin, is home to a large number of wild bananas. Musa borneensis was one of the first Musa species from the island that was described by the Italian botanist Dr. Odoardo Beccari in the nineteenth century. In the twentieth century, the Japanese Prof. Mitsuru Hotta described a closely related variety of M. borneensis, and named it M.flavida. However, each botanist studied different areas of the island and could not observe the close relation to the other varieties. The M. borneensis group from Borneo has been studied extensively in the field during 2001-2004 in Malaysia (Sarawak and Sabah) and Brunei by the authors. Keys and a table of differentiating characteristics of each variety are provided. Six distinct M. borneensis varieties have been identified: alutacea, borneensis, flavida, lutea, phoenicea, and sarawakensis. Four of these varieties are described and illustrated as new varieties. We propose re-classifying M. flavida as a variety rather than as a species, as its degree of differentiation is well within the variations of the other varieties described.

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Ceratopteris thalictroides has been reported to contain three cryptic species, called the south type, the north type and the third type. To obtain a clear understanding of these cryptic species, the somatic and meiotic chromosomes were examined in 18 sporophytes from different localities and three hybrids synthesized among the three types. The examinations revealed that the north type and the third type are tetraploids with 2n=156 and n=78 chromosomes, whereas the south type is a hypotetraploid with 2n=154 and n=77 chromosomes. Several peculiar configurations were occasionally observed at diakinesis in all three types: single rope-shaped bivalents with acrosyndesis, split bivalents with acrosyndetic connections, and quadrivalent or quadrivalent-like configurations. Occasional quadrivalents indicate the presence of several homologies within the genomes of the three types. Many univalents were observed at metaphase I in the hybrid between the south and north types, whereas only a few univalents were occasionally observed in the hybrids between the third and north types, for which a partial cross-sterility had been reported. This suggests that the chromosomal structure has differentiated little between the genomes of the third type and the north type and that the partial cross-sterility is mostly due to genic differentiation between them.

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Somatic chromosome numbers were counted in seven species and six varieties of Isodon occurring in Japan. All of the taxa had 2n=24 chromosomes, indicating that they are diploid. For all taxa except I. umbrosus var. hakusanensis and I. japonicus, chromosome numbers are reported here for the first time. The results suggest that diversification in Japanese taxa of Isodon has occurred at the diploid level, even though some reticulation had been suggested by a preliminary molecular study.

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To make clear the morphological and karyological characteristics and the phylogenetic relationship of the poorly known species 'Asarum cordifolium' from Myanmar, we undertook morphological and karyological studies and phylogenetic analyses of 18 taxa including 14 accessions of Asarum and Saruma. Morphologically, Asarum cordifolium appeared to be assigned to section Asarum in sharing some floral aspects: connate styles, inferior ovary, free sepals beyond the attachment to ovary, and stamens with longer filaments. However, unlike the most species of the section Asarum, the species had foliage leaves alternate to each other and vertically oriented rhizomes, and its somatic chromosome number was 2n=24. Phylogenetic analyses based on ITS regions indicate that A. cordifolium is positioned within the section Asarum and is closely related to A. caudigerum and A. cardiophyllum.

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Harmandia mekongensis (Olacaceae) is reported as a first record from East Kalimantan, Indonesia. In Borneo, this species has been known only twice from Sabah, Malaysia. Its morphological and ethnobotanical notes are provided.

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The large population of Adonis has been known from Hiroshima Prefecture, western Honshu, Japan. The Adonis species was formerly regarded as A. ramosa. However, based on the detailed examinations of flowers and fruits, this species is here identified as A. multiflora. This is the first report of A. multiflora from western Honshu, Japan.

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To obtain more information on the genetic differentiation of Japanese alpine plants, intraspecific variations of chloroplast DNA (cpDNA) of 23 species were investigated. We examined the samples from the populations in Central Honshu, Tohoku, and Hokkaido, Japan; and in Sakhalin, Russia. In the nucleotide sequence of two non-coding regions (trnT-trnL-trnF region and rpl16 intron) of cpDNA, the intraspecific variations were detected in all species, except Carex scita. The species with a relatively high proportion of mutational events (including indels) were Anemone narcissiflora (0.90%), Arenaria arctica (0.74%), Geum calthifolium (0.86%), Hypericum kamtschaticum (1.04%), Pedicularis yezoensis (1.18%), and Trollius riederianus (0.77%).

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