Asarum celsum (Aristolochiaceae, section Heterotropd) and its allies were investigated on Amami-oshima, southwestern Kyushu, Japan. The results of morphological studies showed that three taxa, A. celsum, A. tabatanum, sp. nov., and A. nazeanum, sp. nov., with distinct morphological features and separate geographical ranges could be recognized. Asarum tabatanum is characterized by a larger globular-tubiform calyx tube, the inner surface of which is a complicated network of 19 to 24 longitudinal ridges and inter-connecting transverse ridges, and by longer stylar protuberances. Asarum nazeanum is distinguished from A. celsum and A. tabatanum by its large calyx tube spreading apically, sharp and prominent longitudinal and transverse ridges, and wider calyx tube entrance.

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Two species of Chlamydomonas, Chlamydomonas pseudomacrostigma L. S. Peterfi ex H. Ettl and Chlamydomonas media G. A. Klebs, were examined using light microscopy and the molecular phylogeny of 18S rRNA gene sequences. The molecular phylogeny clearly showed that both species belong to the clade Monadinia and are closely related to Chlamydomonas monadina F. Stein and Chloromonas subdivisa (Pascher & Jahoda) Gerloff & H. Ettl. Based on detailed light microscopy, the chloroplasts of C. pseudomacrostigma were shown to be deep-cup-shaped with a single parietal pyrenoid (Chlamydella-type). Both light microscopy and 18S rRNA gene phylogeny also revealed that an additional strain previously identified as Chlamydomonas monadina actually belong to C. pseudomacrostigma. A newly isolated Japanese strain of C. media was phylogenetically separated from "C media" SAG 10.87, which was further distinguished from C. media by the morphology of the stigma.

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Geranium robertianum L. is considered an endangered species in Japan, while it is invasive in several countries outside Japan. Recently, plants of G. robertianum have been found at several localities, none of which are original stations for G. robertianum in Japan. To determine whether the recently found plants are native Japanese plants or were naturalized from sources outside Japan, we conducted molecular phylogenetic analyses using DNA sequences of the plastid regions of the trn L intron, trnL3'-trnF and trnH-psbA intergenic spacer regions, and the nuclear internal transcribed spacer (ITS). Among 32 samples collected from 21 populations, we recognized three major groups, consisting of 1) recently found plants, 2) indigenous plants, and 3) plants from Britain. Our results suggest that recently discovered plants of G. robertianum in Japan are more likely naturalized from sources outside Japan rather than having escaped from indigenous Japanese populations. The origin of the newly found plants is not known although their origin in Britain is unlikely.

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A new variety of Didymoplexis cornuta J. J. Sm. var. betungkerihunensis Tsukaya & H. Okada (Orchidaceae), found during a botanical survey of Betung Kerihun National Park, West Kalimantan, Borneo, Indonesia, is described and illustrated. This collection resembles D. cornuta J. J. Sm. in having lateral sepals, connate except for the very tip, which is known only from Bogor, Java, Indonesia. Overall colouration also resembles D. cornuta. However, the proposed new variety differs in flower size, has a shorter spur, and lacks a spine-like appendage on the claw near the base of the lip.

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Color variation in Epirixanthes elongata Blume and E. papuana J. J. Sm. (Polygalaceae), discovered during a botanical survey of Betung Kerihun National Park, West Kalimantan, Borneo, Indonesia, is described and illustrated. Both species are rather common in the area, but the color variation, a form of albinism, was rare and found only once in each species.

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Cytologieal studies of the myco-heterotrophic orchid Stereosandra javanica Blume revealed a chromosome number of 2n=116 and 5811. reported here for the first time. The chromosome complement at resting stage was of the complex ehromocenter type, Metaphase chromosomes showed a gradual decrease in chromosome length from 1.5 to 0.9μm. The number, 2n=116, is the highest chromosome number in Japanese wild orchids hitherto recorded and differs from the chromosome numbers in the elosely related genus Epipogium; 2n=72=36II in E. aphyllum SW., 2n=ca. 70=35II in E. roseum (D. Don) Lindl. and 2n=78 in E. japonicum Makino.

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