Vegetation Heterogeneity and Life-Strategy Diversity in the Flora of the Heterogeneous Landscape of Nizanda, Oaxaca, Mexico

We updated the floristic checklist of the Nizanda region, Isthmus of Tehuantepec (southern Mexico), characterized the occurring plant communities based on dominant species, and described the region’s flora according to life form, growth form, growth type, and growth habit spectra. Ten years of botanical exploration, along with surveys in 188 100-m² samples from different vegetation types, provided the baseline floristic information. Ordination and classification analyses were performed to examine the degree of differentiation between communities. Geographical ranges of all species were used to assess biogeographical relationships of this flora. The inventory includes 920 species (553 genera, 124 families). More than one-third of the families were represented by a single species, whereas the 10 richest families had 43% of the species richness. Dendrograms showing plot classification at three taxonomic levels (species, genus and family) revealed savannah as the most strongly differentiated community amid seven vegetation types. Regarding growth forms, forbs and trees prevailed. Phanerophytes were the most common life form category, whereas herbs and woody plants were the dominant growth types. The largest richness for all taxonomic levels was recorded in the tropical dry forest. The expanded floristic knowledge gained for the Nizanda region provided better criteria to revise the classification scheme of its vegetation. Our preliminary biogeographical analysis illustrates the role of the Isthmus of Tehuantepec as a corridor for thermophilous floras between two oceanic watersheds, and as a natural distributional limit for several Mesoamerican plant species.     

The high-rank syntaxa of the rock-cliff and scree vegetation of the mainland Greece and Crete

A revision was undertaken of the high-rank syntaxa of the vegetation occurring in rock fissures, ledges and screes of mainland Greece and Crete. All published phytosociological relevés available were collected and subjected to numerical classification and ordination. Four orders (Androsacetalia vandelii, Onosmetalia frutescentis, Potentilletalia speciosae andPetromaruletalia pinnatae) comprising 8 alliances (one of them new) were distinguished within theAsplenietea trichomanis (rock fissures, clefts, and ledges). The scree vegetation was classified partly within theThlaspietea rotundifolii (Drypidetalia spinosae with 2 alliances) and partly within theDaphno-Festucetea (Saturejo-Scutellarietalia—a new order, with 2 alliances). Ordination revealed clear differences in floristic composition of the alliances distinguished. The studied chasmophytic vegetation of Greece contains a very high proportion of endemics which serve as diagnostic species of the syntaxa. Further, an analysis of chorological species spectra suggested that the chorological homogeneity of a syntaxon should be considered an important diagnostic feature at high-syntaxon levels.     

Phytogeny of genusGlossina (Diptera:Glossinidae) according to ITS2 sequences

The flies of genusGlossina (Diptera: Glossinidae) are an important vector of African trypanosomiases which cause diseases in humans and animals. The ribosomal DNA Internal Transcribed Spacer-2 (ITS-2) region sequences from differentGlossina species were PCR-amplified and analyzed in order to construct a molecular phylogeny for genusGlossina. Trees generated by parsimony confirmed the monophyletic taxonomic placement of genusGlossina wherefusca group species formed the deepest branch followed bymorsitans andpalpalis groups, respectively. The placement ofGlossina austeni by both the traditional morphological and biochemical criteria has been controversial. Results presented here, based on ITS-2 locus sequence analysis, suggest thatGlossina austeni can be placed into a separate subgenerus which forms a sister-group relationship with themorsitans group species.     

The plant communities of theAsplenietea trichomanis in the SW Iberian Peninsula

The rupicolous vegetation of theAsplenietea trichomanis in the south-western Iberian Peninsula is analysed using the methods of the Zürich-Montpellier School. Phytosociological tables, and biogeographical, ecological and floristic data are given for a number of syntaxa. A phytosociological synopsis of the studied vegetation was made for the entire region. Four new syntaxa are described: theCoincyo logirostri-Dianthetum lusitani, Jasiono marianae-Dianthetum lusitani jasionetosum tomentosae, Digitali thapsi-Dianthetum lusitani conopodietosum ramosi andSedo hirsuti-Polypodietum cambrici polypodietosum interjecti.     

Is there environmental differentiation in the <Emphasis Type="Italic">Quercus</Emphasis>-dominated forests of west-central Mexico?

Detailed information on 38 species and 26 environmental variables was recorded from a network of 86 permanent plots across a geographical range of 10 km, in order to determine the patterns of floristic composition in Quercus-dominated forests; to elucidate environmental differentiation in such forests; and to determine whether species are partitioning their environment. To examine likely patterns of floristic composition, a data matrix expressed as relative volume + relative density was used to run non-metric multidimensional scaling. Canonical correspondence analysis extracted the environmental variation that best correlates with the observed patterns of floristic composition. Our results indicate that congeneric Quercus individuals represent the largest proportion of the species pool in the study plots. They coexist with other species having similar ecological requirements in at least three distinct floristic groups. Examination of the two largest groups and their species compositions reveals that one floristic gradient runs across the most xeric zone of the study area, and the second major floristic gradient runs across a mesic zone. The most important environmental variable explaining the observed patterns of floristic composition is altitude, although partial canonical correspondence analysis suggests that micro-habitat heterogeneity (catena position and canopy maturity) was most significant.     

Floristic composition and endemism pattern of vascular plants in Ethiopia and Eritrea

Traditional attempts to delineate floristic regions are typically based on the qualitative analysis of species distribution, often ignoring the phylogenetic relationships among their taxa. Ethiopia and Eritrea are in the Horn of Africa, known as one of the world's biodiversity hotspots. We quantitatively classified the flora of Ethiopia and Eritrea into meaningful geographical units by analyzing the taxonomic and phylogenetic β‐diversity at genera, total species, and endemic species levels at a scale of 0.5° × 0.5° grid cells. Hierarchical clustering was used to quantitatively delimitate the flora and analysis of similarities was used to test the significant difference between the derived groups in taxonomic composition and phylogenetic relatedness. In total, two floristic subprovinces, five floristic districts, and 13 floristic subdistricts, as well as three centers of species endemism associated with three floristic subdistricts were identified. Our results also showed that the species diversity, endemism, and turnover of the highlands in Ethiopia and Eritrea were much higher than the lowlands, indicating that the floristic differences are closely related to the topography of the East African Rift. In this study, we provided a scientific framework for the composition and relationships of the floristic units in the Horn of Africa, and similarly provided a scientific basis for better conservation of the diversity in this region.     

国家Ⅰ级重点保护极危植物藤枣研究进展

国家Ⅰ级重点保护植物藤枣[Eleutharrhena macrocarpa(Diels)Forman]属防己科单种属植物,主要分布于云南南部地区。藤枣因其形态特征和分布式样在防己科植物中较为独特,具有重要的植物系统学和区系地理学研究价值。据相关文献记载,目前发现和记录的藤枣自然种群数量小于60株,种群处于极危状态,面临灭绝风险。国内外与藤枣相关的研究资料也相对匮乏。为及时拯救和关注这一濒危物种,该文在前贤研究的基础上,总结报道了藤枣的分类学简史、科学研究价值、自然种群数量、濒危状况、生物多样性保护地位、区系分布、模式标本认定等方面的最新研究进展,提出了近期的研究目标。期望能对藤枣的准确鉴定、精准调查和进一步深入研究提供基础信息和理论参考。     

Ethnobotanical Study of Traditional Building Materials from the Island of Bali,Indonesia

Ethnobotanical Study of Traditional Building Materials from the Island of Bali, Indonesia. Local knowledge of plant-based building materials has long been part of Balinese tradition. In order to better understand this particular tradition, we carried out a comprehensive ethnobotanical study of 13 aga villages. The data were obtained through semi-structured interviews and questionnaires. Seventy-eight species of plants were identified, comprising 63 genera and 34 families, of which 46% are native to the Flora Malesiana floristic region, 20% to the Indian floristic region, and 17% to the Indochinese floristic region. Ninety-one percent were trees. The most frequently used part was the stem (88%). The main use categories reported for building materials were houses (58%), religious uses (Balinese Hindu temple; 35%), stables (5%), and barns (2%). Thirty-eight percent appeared in more than one use category. Arenga pinnata (Wurmb) Merr. and Magnolia champaca (L.) Baill. ex Pierre were the two species that possessed the highest values in the preference ranking for use value (UV) followed by Artocarpus heterophyllus Lam. Species richness differed substantially between villages according to their different levels of traditional knowledge preservation. Despite the impact of the fast-growing tourist industry and the decline of local knowledge, the Balinese who live in the study areas still depend on locally available indigenous plant species for their building materials. The cultivation of these indigenous plants is in a period of crisis, especially with regard to conservation.     

The rDNA Internal Transcribed Spacer Region as a Taxonomic Marker for Nematodes

The ITS region from a wide taxonomic range of nematodes, including secernentean and adenophorean taxa, and free-living, entomopathogenic, and plant-parasitic species, was evaluated as a taxonomic marker. Size of the amplified product aided in the initial determination of group membership, and also suggested groups that may require taxonomic reevaluation. Congeneric species often displayed identically sized ITS regions, but genera such as Pratylenchus and Tylenchorhynchus had species with large differences in size. ITS heterogeneity in individuals and populations was identified in several nematode taxa. PCR-RFLP of ITS1 is advocated as a method of taxonomic analysis in genera such as Helicotylenchus that contain numerous species with few diagnostic morphological characteristics.     

DNA barcoding of lichenized fungi demonstrates high identification success in a floristic context

? Efforts are currently underway to establish a standard DNA barcode region for fungi; we tested the utility of the internal transcribed spacer (ITS) of nuclear ribosomal DNA for DNA barcoding in lichen-forming fungi by sampling diverse species across eight orders. ? Amplification of the ITS region (ITS1-5.8S-ITS2) was conducted for 351 samples, encompassing 107, 55 and 28 species, genera and families, respectively, of lichenized fungi. We assessed the ability of the entire ITS vs the ITS2 alone to discriminate between species in a taxonomic dataset (members of the genus Usnea) and a floristic dataset. ? In the floristic dataset, 96.3% of sequenced samples could be assigned to the correct species using ITS or ITS2; a barcode gap for ITS is present in 92.1% of species. Although fewer species have a barcode gap in the taxonomic dataset (73.3% with ITS and 68.8% with ITS2), up to 94.1% of samples were assigned to the correct species using BLAST. ? While discrimination between the most closely related species will remain challenging, our results demonstrate the potential to identify a high percentage of specimens to the correct species, and the remainder to the correct genus, when using DNA barcoding in a floristic context.     

Similarity of the edited sequences of Leishmania kinetoplast geneMURF4 (ATPase6)

The primary structure of the edited part of theMURF4 (ATPase6) gene was compared for seven species of flagellateLeishmania. The length of this region in all cases was identical and the sequences proved to be highly homologous. The observed differences appear to correspond to the taxonomic position of the species, which belong to three subgenera,Sauroleishmania, Leishmania, andViannia.     

Novelties in Festuca (Gramineae-Poeae) from southern Bolivia

A new species,Festuca samensis, belonging to theF. lilloi group (subgen.Festuca), is described from the Tarija region in southern Bolivia. The limits of theFestuca lilloi group are revised andF. setifolia, which is here lectotypified, is excluded from this group. Additionally, the first Bolivian record of the Tucuman floristic elementFestuca parodiana of subgen.Subulatae is reported.     

Vegetation on anthropogenic metalliferous soils in the Eastern Alps

A syntaxonomic revision of vegetation of anthropogenic metalliferous habitats (mine spoils of lead, zinc and copper mining) in the Eastern Alps (Austria, Germany, Italy and Slovenia) was made. The communities studied belong to theThlaspietea rotundifolii (Linaria alpina-Cerastium uniflorum comm.,Papaveri kerneri-Thlaspietum kerneri, Violetum dubyanae, Thlaspietum cepaeifolii, Thlaspietum rotundifolii, Scrophulario juratensis-Erysimetum sylvestris, Minuartia gerardii-Silene glareosa comm.,Epipactido atrorubentis-Silenetum glareosae andSileno alpestris-Moehringietum muscosae) and to theAsplenietea trichomanis (Sileno rupestris-Asplenietum). There is neither floristic support nor syntaxonomic justification for the concepts of theGalio anisophylli-Minuartion vernae, theVioletalia calaminariae and theVioletea calaminariae in the Eastern Alps. These units should be included within theThlaspion rotundifolii, Thlaspietalia rotundifolii andThlaspietea rotundifolii, respectively.     

Cecropia telenitida Cuatrec. (Urticaceae: Cecropieae): Phytochemical diversity,chemophenetic implications and new records from Central America

The Neotropical genus Cecropia is the largest genus of Cecropieae in the Urticaceae family with 61 described species. For many years, the taxonomic study of Cecropia has been based on morphological and anatomical data. However, recent studies have shown that chemical entities present in Cecropia can be used to establish differences between species providing important additional support on its taxonomic classification. The goal of the present study was to contribute to the phytotaxonomic knowledge of this genus to better inform taxonomic decisions. In addition, this is the first time that chemical constituents have been described in the leaves of Cecropia telenitida Cuatrec., a species that until now had not been reported in Central America. We characterized and quantified the polyphenolic composition of the methanol leaf extract of C. telenitida using UPLC-DAD-MS and HPLC-DAD, respectively. Phytochemical analysis showed that this extract was rich in chlorogenic acid and flavone C-glycosides, with isoorientin and isoorientin 2″-O-xyloside as the main compounds. Our data showed a lower chemical diversity and metabolite concentrations than other related species. Morphological, distributional and taxonomic notes, images of the plant and phytochemical comparisons between C. telenitida and selected congeners from Panama are also provided.     

Nomenclatural changes in some intermountain penstemons (Scrophulariaceae)

Fifteen new combinations and one new binomial inPenstemon, to be used in a floristic treatment of the genus in theIntermountain Flora, are published herewith.     

A biosystematic analysis of the Caltha leptosepala (Ranunculaceae) complex in the Rocky Mountains I. Chromatography and cytotaxonomy

Part one of a biosystematic study of theCaltha leptosepala complex in the Rocky Mountains involves a brief history of the taxonomic problem in addition to analyses of phenolic chromatography and cytotaxonomy. Data obtained from the natural populations sampled support the premise that only one species,Caltha leptosepala, can be taxonomically justified for the Rocky Mountains.     

Allosteric Regulation in a Family of Enterobacterial Aspartate Transcarbamylases: Intramolecular Transmission of Regulatory Signals in Chimeric Enzymes

Several enterobacterial aspartate transcarbamylases (ATCases) exhibit a [2(c₃):3(r₂)] quaternary structure analogous to that of theEscherichia colienzyme. Despite their conserved quaternary structures, these enzymes present substantial differences in the co-operativity of substrate binding and in their allosteric regulation by nucleotide effectors. A comparison between different enzymatic species provides an opportunity to expand our understanding of the molecular basis of allostery in ATCase. Chimeric ATCases were constructed by exchanging subdomain regions involved in quaternary structural features, such as the r1-c4 regulatory-catalytic subunit interface analyzed in this study, in order to define the involvement of this interface in the several components of allosteric regulation. The r1-c4 interface was found to constitute an essential element for the recognition and the transmission of the ATP regulatory signal in theSerratia marcescensand theProteus vulgarisATCases, as it does in theE. coliATCase. Besides, the specific amino acid composition of the C-terminal region of the regulatory chain and its interactions with the amino acid residues in the 240s loop of the catalytic chain (r1-c4 interactions) were found to modulate the amplitude of the enzyme's response to ATP. The C-terminal region of the regulatory chain did not appear to participate directly in the regulation of the three native ATCases by CTP. Even when CTP acts as an activator, as in theP. vulgarisandS. marcescensATCases, its signal follows a route distinct from that of the general activator ATP. Synergistic inhibition by CTP and UTP was found to involve the transmission of a specific UTP signal. This signal appeared different in the various ATCases, involving the C-terminal region of the regulatory chain in theE. coliandS. marcescensATCases but not in theP. vulgarisATCase.     

A new species of Castilleja (Orobanchaceae) from the central Sierra Madre Occidental, Mexico, and an annotated key to the Castilleja species of that region

Castilleja holmgrenii is described from several collections made in the Sierra Madre Occidental in southeast Sinaloa and adjacent southwest Durango, Mexico. The new species is a member of subgenus and sectionCastilleja. This apparently rare species is presently known from two small, geographically restricted populations. Also provided are a list of theCastilleja species of this region with notes on their status and distribution, a key for their identification, and nomenclatural and taxonomic notes concerning some of the species.     

The evolution of Dianthus polylepis complex (Caryophyllaceae) inferred from morphological and nuclear DNA sequence data: one or two species?

Dianthus polylepis complex consists of two already known endemic species, Dianthus polylepis and D. binaludensis, in Khorassan-Kopetdagh floristic province. The taxonomic position of these species has long been debated. The aim of the present study is to shed light on the evolutionary relationships of the members of the complex using morphological and molecular data. In morphological study, firstly, 56 vegetative and floral characters were measured on 33 specimens of the both species. Multivariate analyses were performed on 25 (out of 56) significantly discriminating morphological traits. In molecular study, we sequenced alleles obtained from a region between 2nd and 6th exons of the gene coding for the enzyme dihydroflavonol 4-reductase copy1 (DFR1). Morphological results show that most of a priori identified accessions were not grouped in a posteriori classification. It is difficult to discriminate D. polylepis from D. binaludensis in morphological continuum among the accessions. Results obtained from the molecular data indicated no monophyly for the members of the D. polylepis complex. Consistency between the morphological and molecular results shows that D. polylepis and D. binaludensis were not morphologically and molecularly well differentiated. Therefore, we propose a new combination as D. polylepis subsp. binaludensis.