The new genus Roodebergia B. Nord. (Compositae-Astereae) is described from the Cape Province, South Africa, with a single species, R. kitamurana B. Nord. sp. nov. The closest affinities may be with Felicia Cass. and other African members of the Amellus Group.

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A new species or Yoania, Yoania flava, from southern Nagano, central Japan is described. The species has creamy yellow flowers and was formerly identified as Y. amagiensis from the Pacific Ocean side od Honshu. Yoania flava is morphologicically more similar to Y. japonica than to Y. amagiensis, but is distinguishable from Y.japonica by the nearly entire mid-lobe of the lip. DNA sequences from the ITS (internal transcribed spacer) region of the 18S-26S nuclear ribosomal DNA and rpL 16 intron further support the hypothesis that Y.flava is more akin to Y. japonica than to Y. amagiensis.

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Two new species of Diplobryum are described from Laos, bringing the number of species in the genus to four. Diplobryum vientianense (n. sp.) resembles D. minutale in the foliose root and longitudinally split spathella. Diplobryum koyamae (n. sp.) is similar to D. ramosum in the long, ramified, flower-bearing, floating root. In root features D. koyamae is also similar to some species of Polypleurum. The phylogeny of the diversified genus Diplobryum remains uncertain. Recent collections and a comparison of Podostmaceae in Thailand and Laos indicate the necessity of further field research to better understand the flora and taxonomy of the family of Laos. A list of the species of Laos Podostemaceae is provided.

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The genetic relationships between the Higashi-Iyayama population and some other populations of Ranunculus japonicus, and two other closely related species, R. yakushimensis and R. acris var. nipponicus, were assessed morphologically, karyotypically, electrophoretically and by cross experiments. Plants of the Higashi-Iyayama population showed a leaf shape and the flowering time being similar to those of other R. japonicus populations but different from those of R. acris var. nipponicus and R. yakushimensis populations. On the other hand, plants of the Higashi-Iyayama population differed from those of other R. japonicus populations in both achene shape and plant size. These results suggest that plants of the Higashi-Iyayama population are not hybrids between R. japonicus and R. acris var. nipponicus, but rather are derivatives with some new characters from R. japonicus. The allozymic analysis and cross experiments show that the Higashi-Iyayama population is closely related to those of other R. japonicus and R. yakushimensis, but less closely to those of R. acris var. nipponicus.

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Mertensia pterocarpa var. yezoensis of Hokkaido has been distinguished from M. pterocarpa var. pterocarpa of the southern Kurils mainly by the hairiness and shape of the calyx lobes. The hairiness on the outside of the calyx lobes exhibits a geocline from glabrous or sparsely strigose in the southern Kurils on the one end, through eastern Hokkaido, the Taisetsu Range and the Yubari Range, to densely strigose on Mt. Tottabetsu of the Hidaka Range on the other. The shape of the calyx lobes shows no such geocline. The calyx sometimes shows characteristic features for each mountain ; e. g., narrow calyx lobes on Mt. Yubari, but otherwise can be very variable even on a single mountain ; e. g., lobes lanceolate to deltoid on Mt. Tottabetsu. Principal component analysis using six morphological characters indicated that the range of variation in plants of the Hidaka-Yubari Ranges (typical var. yezoensis) is a distinct from that in plants of the southern Kurils (typical var. pterocarpa), but the range of variation in plants of the Taisetsu Range is broad and encompasses ranges of variation of both the Hidaka-Yubari and southern Kuril populations. The plants of M. pterocarpa from the southern Kurils, the Taisetsu Range, and the Hidaka-Yubari Ranges are morphologically similar. Plants from Mt. Nagayama, half of the plants from Mt. Kami-Furano and some plants from Mt. Byobu of the Taisetsu Range are especially similar to those of the southern Kurils and should be treated as var. pterocarpa. Not only var. yezoensis but also var. pterocarpa, together with plants intermediate between them, grow on Hokkaido.

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Somatic chromosome numbers were examined for 28 species and two varieties of seven genera in Asclepiadaceae collected in Japan. The chromosome numbers of 21 species and two varieties were newly reported here. All taxa examined had chromosome numbers of 2n=22 except for 2n-44 in Cynanchum caudatum var. caudatum, Vincetoxicum ambiguum, V. sublanceolatum var. sublanceolatum, V. sublanceolatum var. macranthum and 2n=24 for Cynanchum boudieri. In Cynanchum caudatum, chromosome number of 2n=22 was also found as well as 2n=44, indicating that intraspecific polyploidy exists in the species.

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We report the somatic chromosome numbers of Plagiogyria adnata, P. yakushimensis, and a putative hybrid between them. The chromosome number of P. adnata was determined to be 2n=260 (tetraploid, x=65) and 2n=325 (pentaploid, a new count). In P. yakushimensis, two cytotypes, 2n=260 (tetraploid) and 2n=390 (hexaploid), are reported for the first time. A pentaploid individual with 2n=c. 325 is considered to be a hybrid between P. adnata and P. yakushimensis, based on cytology and leaf morphology. The present study indicates that sympatric populations of the two species have cytologically and morphologically diversified as a result of polyploidization and hybridization.

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Dianthus superbus and D. shinanensis are common gynodioecious herbs occurring in grasslands and riverbeds in central Honshu of Japan. We investigated the reproductive nature and pollination systems of the two species to determine what differences in reproductive success and pollination might exist between these taxa and between female and hermaphrodite plants, and whether seed production was limited by pollen availability. In D. superbus the female plants produced more numerous seeds than the hermaphrodite plants, or produced seeds equal to the hermaphrodite ones in natural populations. Both hermaphrodite and female flowers of the species were largely pollinated by large-sized butterflies and hawkmoths sucking the nectars, and did not differ from each other in frequency of flower visitors. In D. shinanensis, on the other hand, the seed set percentages were significantly lower in the female plants than in the hermaphrodite plants. The effective pollinators of the species were mainly middle-sized butterflies sucking the nectars and bees and hover-flies feeding on pollen grains, but the frequency of flower visitors was obviously lower in the female plants than in the hermaphrodite plants. The lower female reproductive success (I. e., seed production) of D. shinanensis may be caused by the reduced visits of the insect pollinators due to lacking pollen rewards.

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Morphological characteristics of the heterostylous subshrub, Reinwardtia indica occurring in Mandalay Division, Myanmar, were examined. The species is typically distylous, and shows dimorphism in pollen size, exine sculpture of pollen grains, stigma size and length of stigmatic papillae. Pollen grains from long-styled morphs are significantly smaller in size than those of short-styled morphs. Exine of the pollen grains from the two morphs has two kinds of processes, verrucate and spinulous ones. These processes are longer and more swollen in the short-styled morphs than in the long-styled morphs and appear more densely packed in the long-styled morphs. Unlike most of the heterostylous species, the species concerned here was characterized by having the stigmatic papillae which were obviously slender and longer in the short-styled morphs than in the long-styled morphs.

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To understand the morphological and ecological diversity of Syzygium in the Bonin Islands, we examined 269 individuals from 37 localities in the Bonin Islands and the Nansei Islands for vegetative and floral characters. The vegetation of their respective habitats was also examined as an indicator of environmental conditions. Three groups of Syzygium in the Bonin Islands were distinguishable from the Nansei Islands group by principle component analysis (PCA). These four groups had unique morphological sets. The three groups in the Bonin Islands generally grow in different vegetation and seldom occur sympatrically, suggesting habitudinal segregation among the groups. One group of plants on the Bonin Islands is distributed on both the Chichi-jima Islands and the Haha-jima Islands and shows remarkable morphological variation of the Haha-jima Islands compared with those of the Chichi-jima Islands. In particular, many individuals in the southern area of the Haha-jima Islands have peculiar morphological features not found in the others. Furthermore, these distinctive Haha-jima individuals grow in Distlylium-Schima dry forests, which are rare for this group on the Chichi-jima Islands. The morphological differentiation of this group may represent an initial stage of the evolutionary process of adapting to environmental conditions.

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Myriophyllum oguraense Miki, described in 1934 and hitherto regarded as a Japanese endemic, has been found to occur widely as a native plant in China. The discovery of this taxon in China shows that M. oguraense occurs more widely in eastern Asia and falls within the Sino-Japanese distribution pattern.

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