Showing papers in "Taxon in 2013"

Legume phylogeny and classification in the 21st century: Progress, prospects and lessons for other species-rich clades

Abstract: The Leguminosae, the third-largest angiosperm family, has a global distribution and high ecological and economic importance We examine how the legume systematic research community might join forces to produce a comprehensive phylogenetic estimate for the ca 751 genera and ca 19,500 species of legumes and then translate it into a phylogeny-based classification We review the current state of knowledge of legume phylogeny and highlight where problems lie, for example in taxon sampling and phylogenetic resolution We review approaches from bioinformatics and next-generation sequencing, which can facilitate the production of better phylogenetic estimates Finally, we examine how morphology can be incorporated into legume phylogeny to address issues in comparative biology and classification Our goal is to stimulate the research needed to improve our knowledge of legume phylogeny and evolution; the approaches that we discuss may also be relevant to other species-rich angiosperm clades

A worldwide molecular phylogeny and classification of the leafy spurges, Euphorbia subgenus Esula (Euphorbiaceae)

Abstract: The leafy spurges, Euphorbia subg. Esula, make up one of four main lineages in Euphorbia. The subgenus comprises about 480 species, most of which are annual or perennial herbs, but with a small number of dendroid shrubs and nearly leafless, pencil-stemmed succulents as well. The subgenus constitutes the primary northern temperate radiation in Euphorbia. While the subgenus is most diverse from central Asia to the Mediterranean region, members of the group also occur in Africa, in the Indo-Pacific region, and in the New World. We have assembled the largest worldwide sampling of the group to date (273 spp.), representing most of the taxonomic and geographic breadth of the subgenus. We performed phylogenetic analyses of sequence data from the nuclear ribosomal ITS and plastid ndhF regions. Our individual and combined analyses produced well-resolved phylogenies that confirm many of the previously recognized clades and also establish a number of novel groupings and place- ments of previously enigmatic species. Euphorbia subg. Esula has a clear Eurasian center of diversity, and we provide evidence for four independent arrivals to the New World and three separate colonizations of tropical and southern Africa. One of the latter groups further extends to Madagascar and New Zealand, and to more isolated islands such as Reunion and Samoa. Our results confirm that the dendroid shrub and stem-succulent growth forms are derived conditions in E. subg. Esula. Stem- succulents arose twice in the subgenus and dendroid shrubs three times. Based on the molecular phylogeny, we propose a new classification for E. subg. Esula that recognizes 21 sections (four of them newly described and two elevated from subsectional rank), and we place over 95% of the accepted species in the subgenus into this new classification.

Phylogenetics, morphological evolution, and classification of Euphorbia subgenus Euphorbia

Abstract: Euphorbia subg. Euphorbia is the largest and most diverse of four recently recognized subgenera within Euphorbia and is distributed across the tropics and subtropics. Relationships within this group have been difficult to discern due mainly to homoplasious morphological characters and inadequate taxon sampling in previous phylogenetic studies. Here we present a phylogenetic analysis of E. subg. Euphorbia, using one nuclear and two plastid regions, for the most complete sampling of molecular sequence data to date. We assign 661 species to the subgenus and show that it is comprised of four highly supported clades, including a single New World clade and multiple independent lineages on Madagascar. Using this phylogenetic framework we discuss patterns of homoplasy in morphological evolution and general patterns of biogeography. Finally, we present a new sectional classification of E. subg. Euphorbia comprising 21 sections, nine of them newly described here.

Global legume diversity assessment: Concepts, key indicators, and strategies

Abstract: While many plant species are considered threatened under anthropogenic pressure, it remains uncertain how rapidly we are losing plant species diversity. To fill this gap, we propose a Global Legume Diversity Assessment (GLDA) as the first step of a global plant diversity assessment. Here we describe the concept of GLDA and its feasibility by reviewing relevant approaches and data availability. We conclude that Fabaceae is a good proxy for overall angiosperm diversity in many habitats and that much relevant data for GLDA are available. As indicators of states, we propose comparison of species richness with phylogenetic and functional diversity to obtain an integrated picture of diversity. As indicators of trends, species loss rate and extinction risks should be assessed. Specimen records and plot data provide key resources for assessing legume diversity at a global scale, and distribution modeling based on these records provide key methods for assessing states and trends of legume diversity. GLDA has started in Asia, and we call for a truly global legume diversity assessment by wider geographic collabora- tions among various scientists.

Molecular phylogenetics and character evolution of Cannabaceae

Abstract: Cannabaceae includes ten genera that are widely distributed in tropical to temperate regions of the world. Because of limited taxon and character sampling in previous studies, intergeneric phylogenetic relationships within this family have been poorly resolved. We conducted a molecular phylogenetic study based on four plastid loci (atpB-rbcL, rbcL, rps16, trnL-trnF) from 36 ingroup taxa, representing all ten recognized Cannabaceae genera, and six related taxa as outgroups. The molecular results strongly supported this expanded family to be a monophyletic group. All genera were monophyletic except for Trema, which was paraphyletic with respect to Parasponia. The Aphananthe clade was sister to all other Cannabaceae, and the other genera formed a strongly supported clade further resolved into a Lozanella clade, a Gironniera clade, and a trichotomy formed by the remaining genera. Morphological ancestral state reconstructions indicated the complex evolution pattern of most analyzed morphological characters, and it is difficult to identify morphological synapomorphies for most clades within Cannabaceae.

Reappraisal of sectional taxonomy in Musa (Musaceae)

Abstract: The present work is part of a continuing study on Musa taxa by the author. Several molecular analyses support accep- tance of only two Musa sections, M. sect. Musa and M. sect. Callimusa. Musa sect. Rhodochlamys is synonymized with M. sect. Musa and M. sect. Australimusa and M. sect. Ingentimusa are treated as synonyms of M. sect. Callimusa. Species lists are provided for the two accepted sections.

Phylogeny of Calliandra (Leguminosae: Mimosoideae) based on nuclear and plastid molecular markers

Abstract: We reconstructed phylogenetic relationships in Leguminosae subfam. Mimosoideae tribe Ingeae using 135 sequences from the nuclear (ITS) and 119 from the plastid (trnL-F) genome, representing 23 of the 36 currently recognized genera in the tribe with newly generated sequences of Blanchetiodendron, Guinetia, Macrosamanea, Thailentadopsis and Viguieranthus and an extensive sampling of Calliandra. Only two of the five Neotropical generic alliances of Barneby & Grimes (1996) were supported as monophyletic. Calliandra is resolved as monophyletic with the inclusion of Guinetia. The five previously proposed sections within Calliandra were not supported by our study. Nevertheless, based on these results, a new infrageneric classifica- tion is proposed for Calliandra, and the African species of the genus are assigned to a new genus, Afrocalliandra. Three new sections are proposed for Calliandra: (1) sect. Tsugoideae based on C. ser. Tsugoideae, with four species from northwestern South America; (2) sect. Septentrionales, with six species distributed in dry areas from the United States to Mexico and (3) sect. Monticola, which consists of species restricted to the Espinhaco range of Brazil; these latter species form a clade with low levels of sequence variation, a potential indicator of the recent diversification of this group.

Molecular phylogeny of the Campanula pyramidalis species complex (Campanulaceae) inferred from chloroplast and nuclear non-coding sequences and its taxonomic implications

Abstract: The Campanula pyramidalis complex is a group of closely related taxa with a distribution across the Balkans, from the Gulf of Trieste in the north to the Peloponnese Peninsula in the south, with small disjunct parts of the range in the south Apennines. Although 21 taxa were described within this complex, only three, C. pyramidalis, C. versicolor, and C. secundiflora, have been generally accepted in recent synoptical taxonomic treatments. Our molecular phylogenetic analyses based on sequences of three non-coding chloroplast regions (psbA-trnH, psbZ-trnfM, trnG-trnS) as well as of nuclear ribosomal internal transcribed spacers (nrITS), lend strong support to the recognition of several lineages which only partially correspond to generally accepted taxonomic concepts. Molecular data presented in this study showed that C. pyramidalis is a polyphyletic assemblage that segregates into three distinct lineages, one of which is described here as a new species, C. austroadriatica sp. nov. The lectotype of C. pyramidalis, redefined in a strict sense, is designated. Neither C. versicolor nor C. secundiflora were found to be strictly monophyletic, but their monophyly could not be rejected. Morphological and biogeographical implications are discussed.

Biogeography: Where do we go from here?

Abstract: Biogeography is a multidisciplinary science concerned with how and why organisms are distributed as they are on Earth. It links fields such as systematics, ecology, paleontology, and climatology, and occupies a central position in evolutionary biology, being fundamental to the study of processes such as speciation and adaptive radiation. Here we provide a brief overview of some particularly dynamic areas of inquiry and offer some perspectives on future directions for the field. We hope that some historical debates, such as those over the importance of dispersal, or the validity of molecular dating, are finally being put to rest. Over the last decade, biogeography has become increasingly integrative, and has benefited from advances in statistical methods for inferring geographic range dynamics in a phylogenetic context, molecular estimation of lineage divergence times, and modeling lineage birth and death. These are enabling greater insights into patterns of organismal diversification in time and space. In the next decade, analytical challenges are emerging on several fronts. For example, phylogenies are increasing in size and taxonomic breadth and new sequencing technologies enabling phylogenetic and phylogeographic datasets are increasingly genomic in depth. In addition, geographic occurrence data are accumulating in online repositories, yet tools for data mining and synthetic analysis are lacking for comparative multi-lineage studies. Biogeography is thus entering an era characterized by phylogenomic datasets, increasingly comprehensive sampling of clades, and interdisciplinary synthesis. We anticipate continued progress in our understanding of biodiversity patterns at regional and global scales, but this will likely require greater collaboration with specialists in bioinformatics and computational science. Finally, it is clear that biogeography has an increasingly important role to play in the discovery and conservation of biodiversity. Lessons learned from biogeographic studies of islands are being applied to better understand extinction dynamics as continental ecosystems become more fragmented, and phylogeography and ecological niche modeling offer innovative paths toward the discovery of previously unknown species distributions and priority areas for conservation. The future of biogeography is bright and filled with exciting challenges and opportunities.

The potential of genomics in plant systematics

Abstract: Next-generation sequencing (NGS) has revolutionized molecular systematics as well as population and conservation genetics. It is now possible to obtain enormous amounts of gene sequence data from any species in a short time at low cost. More technological advances are on the horizon, ensuring that this trend will continue throughout the coming decade. These rapid advances provide unprecedented opportunities in systematics; they also pose new challenges, requiring that the next generation of systematists be well-versed in new skill sets (e.g., bioinformatics). As examples of the potential of NGS, it is now possible to develop genetic resources for any plant system that poses intriguing evolutionary questions. During the next decade many new "evolutionary model systems" will become available as systematists rapidly develop the necessary genetic/genomic frameworks for many previously unstudied plants. Phylogenetic reconstruction will be conducted at an unprecedented pace at both deep and fine scales with datasets of numerous taxa and genes—this includes rapid progress on assembling a more com- prehensive Tree of Life for green plants. For example, complete plastid genome sequencing is now routinely facilitating analyses of hundreds of taxa at deep levels, as well as enabling complete plastid genome phylogeographic analyses at the population level. Gene capture methods hold enormous promise for the rapid and inexpensive analyses of complete plastid genomes, as well as studies of hundreds of selected (targeted) nuclear loci. NGS has also had a big impact on population genetics, initially by dramatically simplifying microsatellite marker development, but more recently by opening new possibilities through vari- ous genotyping-by-sequencing (GBS) approaches that have great potential to expand on the types of questions that can be addressed at the population level. Transcriptome sequencing has enabled the construction of large datasets of nuclear genes while also providing a wealth of plastid and mitochondrial genes. NGS has also facilitated probe development for studies of chromosomes using FISH (fluorescence in situ hybridization). NGS is also making the rapid sequencing of complete nuclear genomes routine, thus transforming our field and opening up new avenues of systematic endeavor in comparative genomics. However, even as sequencing costs drop and technological advances make complete nuclear genome sequencing more com - monplace, genome assembly will remain a major challenge.

A molecular phylogeny and classification of the largely succulent and mainly African Euphorbia subg. Athymalus (Euphorbiaceae)

Abstract: Euphorbia subg. Athymalus consists of approximately 150 species and is one of the four main lineages that comprise the species-rich genus Euphorbia. Most species in the subgenus are stem succulents with greatly reduced leaves, but there are also leafy herbs, shrubs, trees and geophytes. The subgenus is restricted to arid regions of the Old World. Most species are found in sub-Saharan Africa, with one in Macaronesia and adjacent parts of western Africa, a few in the Arabian Peninsula (one of which extends into Iran) and one native to Madagascar. Twenty-three species are endemic to the northeastern Horn of Africa (SE Ethiopia, Socotra, Somalia), while 72 species are restricted to southern Africa (including Botswana, Lesotho, Namibia, South Africa and Swaziland). Sixty of those are endemic to South Africa alone, where they are particularly associated with the semi-arid west and south of the country in the Greater Cape Floristic Region and the Nama Karoo Region. We sampled 88 species and analyzed data from the nuclear ribosomal ITS and plastid ndhF regions. Analyses of the separate and combined datasets produced phylogenies that confirm the monophyly of E. subg. Athymalus and the placement of E. antso from Madagascar as sister to the rest of the subgenus. Our analyses also show that the subgenus consists of a grade of early-diverging lineages that are relatively poor in species and that the major radiation of succulent species in southern Africa forms a highly supported clade (E. sect. Anthacanthae). Species-level relationships within this southern African clade, however, remain largely unresolved. Our phylogenetic hypotheses allow us to propose a new classification for E. subg. Athymalus where seven sections are recognized, two of which are newly described. The large southern African E. sect. Anthacanthae is further divided into five subsections, and four series are recognized in E. subsect. Florispinae.

Towards a phylogenetic classification of the climbing fern genus Arthropteris

Abstract: We inferred the classification of the Paleotropical climbing fern genus Arthropteris and its close relative Psammio­ sorus, a monotypic genus endemic to Madagascar. The classification of these ferns has until now been poorly understood. To address this, we sampled more than half of the species diversity covering the whole range of the genus including the outlying occurrence at the Juan Fernandez Islands. To reconstruct phylogenetic relationships, we obtained DNA sequences from up to six plastid genome regions, including coding and non-coding regions, for these two genera and representatives of all fami- lies of the eupolypod I clade, with an emphasis on the Tectariaceae. These data were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference. We also obtained divergence time estimates. Three questions were addressed. (1) We established that Arthropteris and Psammiosorus form a well-supported clade representing a separate taxon based on their morphological distinctiveness, phylogenetic relationships, and separation since the Eocene from other accepted families of eupolypod ferns. (2) Psammiosorus was found to be nested within Arthropteris. (3) Our analyses supported recognition of a previously doubted species endemic to the karst regions of southern China and northern Vietnam. As a consequence of our results, we describe the new family Arthropteridaceae and introduce the new combination Arthropteris paucivenia for the Madagascan endemic previously treated under Psammiosorus.

Species diversity and reticulate evolution in the Asplenium normale complex (Aspleniaceae) in China and adjacent areas

Abstract: The Asplenium normale complex contains the widespread A. normale and several geographically restricted spe- cies: A. boreale, A. hobdyi, A. kiangsuense, A. oligophlebium and A. shimurae. The taxonomy of this group is unclear with some entities treated infraspecifically or as synonyms. Furthermore, the existence of diploids and tetraploids in this species complex is suggestive of reticulate evolution. In order to formulate a natural classification and to investigate the relationships in this complex, phylogenetic analyses of plastid and nuclear sequence data and inference of ploidy level were used to assess the distinctiveness of putative taxonomic units and their relationships. The Asplenium normale complex was recovered as a monophyletic group comprising six principal chloroplast lineages. The results support the hypothesis that A. normale s.l. contains several species. Based on our inferences, we outline an improved species classification recognizing three diploid and four tetraploid entities. Incongruence of chloroplast and nuclear phylogenies was interpreted to be a result of recurrent reticulation events in the A. normale complex.

Toward a new circumscription of the twinsorus-fern genus Diplazium (Athyriaceae): A molecular phylogeny with morphological implications and infrageneric taxonomy

Abstract: Diplazium and allied segregates (Allantodia, Callipteris, Monomelangium) represent highly diverse genera belong- ing to the lady-fern family Athyriaceae. Because of the morphological diversity and lack of molecular phylogenetic analyses of this group of ferns, generic circumscription and infrageneric relationships within it are poorly understood. In the present study, the phylogenetic relationships of these genera were investigated using a comprehensive taxonomic sampling including 89 species representing all formerly accepted segregates. For each species, we sampled over 6000 DNA nucleotides of up to seven plastid genomic regions: atpA, atpB, matK, rbcL, rps4, rps4-trnS IGS, and trnL intron plus trnL-trnF IGS. Phylogenetic analyses including maximum parsimony, maximum likelihood and Bayesian methods congruently resolved Allantodia, Cal - lipteris and Monomelangium nested within Diplazium; therefore a large genus concept of Diplazium is accepted to keep this group of ferns monophyletic and to avoid paraphyletic or polyphyletic taxa. Four well-supported clades and eight robust sub- clades were found in the phylogenetic topology. Reconstruction of the evolutionary pattern of morphological characters, such as dissections of leaves, petiole/rachis scales, and shapes of sori, recovered some character combinations of systematic value for infrageneric classification. In light of morphological characters and our molecular phylogeny, a re-defined Diplazium and an infrageneric classification are proposed.

Towards a natural classification of Sapotaceae subfamily Chrysophylloideae in Oceania and Southeast Asia based on nuclear sequence data

Abstract: Generic limits within subfamily Chrysophylloideae (Sapotaceae) from Oceania and Southeast Asia are reconciled based on a molecular phylogeny. We analysed sequences of nuclear ribosomal DNA (ETS, IT ...

Phylogeny of Hedyotis L. (Rubiaceae Spermacoceae) : Redefining a complex Asian-Pacific assemblage

Abstract: The genus Hedyotis (Rubiaceae: Spermacoceae) has long served as a repository for tropical herbaceous species that do not fit readily into other genera. Circumscribed broadly the genus becomes a highly heterogeneous assembly, but relationships of Hedyotis have been difficult to resolve and it has proven very difficult to circumscribe the genus in a more narrow sense. Here we present Bayesian phylogenetic analyses of Hedyotis using plastid (rps16, petD) and nuclear (ITS, ETS) sequence data to resolve monophyletic lineages, to test former taxonomic hypotheses, and to revise the taxa within a well-supported evolutionary framework. Four hundred and sixty-seven sequences representing 129 accessions, never previously included in any phylogenetic analyses, are newly reported. Hedyotis, as previously circumscribed, is polyphyletic, but all investigated species, except for Hedyotis coronaria, are resolved in one of three well-supported monophyletic groups. The largest clade includes all investigated species of Hedyotis from the Indian subcontinent as well as three groups of species with primarily Chinese distributions. The type species of Hedyotis (H. fruticosa) is resolved with the Indian subcontinent species and following previous suggestions this group is referred to as Hedyotis s.str. Species currently recognized under the generic names Metabolos and Pleiocraterium are resolved in Hedyotis s.str. The second-largest group comprises a series of smaller, but well-supported, clades including the Leptopetalum clade, the genus Kadua, an unnamed group distributed in Asia and the Pacific, and a large Asian group referred to here as the ExallagelDimetia clade. The third group includes a few SE Asian Hedyotis, as well as all investigated species of the genus Neanotis. Hedyotis coronaria is not closely related to other species from Asia and is resolved with Spern2acoce hispida. The analyses indicate that diplophragmous capsules and fruticosa-type seeds occur outside of Hedyotis s.str., and several species suggested to have these features are resolved in the ExallagelDimetia clade. Species suggested to have indehiscent capsules, a feature used by Bremekamp to characterize the genus Exallage, are also resolved in both the ExallagelDimetia clade and in Hedyotis s.str., but a close examination indicates that the capsules are not truly indehiscent in the Hedyotis s.str. species. One species of Metabolos and one species of Pleiocraterium are given new species names, and one species of Pleiocrateriam is transferred to Hedyotis and three species of Hedyotis are transferred to Neanotis.

Partial generic revision of Barbula (Musci: Pottiaceae): Re-establishment of Hydrogonium and Streblotrichum, and the new genus Gymnobarbula

Abstract: Large genera, that were defined using a restricted suite of morphological characters, are particularly prone to be polyphyletic. We analysed a representative selection of species traditionally assigned to the genus Barbula, believed to represent the largest genus of the moss family Pottiaceae, but which recently was suggested to be polyphyletic. Special attention was paid to species traditionally assigned to Barbula sect. Hydrogonium and sect. Convolutae, in which phylogenetic relationships are likely to be incongruent with morphological traits, which could have evolved in adaptation to hydric and otherwise extreme habitats. Our phylogenetic analysis was based on nrITS and chloroplast rps4 and trnM-trnV sequence data and resolved only the type of the genus, B. unguiculata, plus B. orizabensis, in subfamily Pottioideae, while most of the species occurring in the Northern Hemisphere are part of Trichostomoideae and need to be recognized within the re­established and partly re­defined genera Hydrogonium and Streblotrichum. The phylogenetically and morphologically divergent B. bicolor needs to be removed from Streblotrichum to a newly described genus, Gymnobarbula. Numerous taxonomic changes and nomenclatural novelties, resulting from the molecular, morphological and nomenclatural studies are proposed for taxa of Hydrogonium, particularly within the H. consanguineum clade. Lectotypes are selected for Tortula angustifolia Hook. & Grev. (≡ Hydrogonium angus- tifolium (Hook. & Grev.) Jan Kucera, comb. nov.), Tortula consanguinea Thwaites & Mitt. (≡ Hydrogonium consanguineum (Thwaites & Mitt.) Hilp.) and Tortula flavescens Hook. & Grev. (= Hydrogonium consanguineum (Thwaites & Mitt.) Hilp.).

Genetic, cytological and morphological differentiation within the Balkan‐Carpathian Sesleria rigida sensu Fl. Eur. (Poaceae): A taxonomically intricate tetraploid‐octoploid complex

Abstract: Reconstruction of relationships among populations of the morphologically polymorphic and taxonomically intricate Sesleria rigida sensu Fl. Eur. based on Amplified Fragment Length Polymorphisms (AFLPs) revealed four clearly differentiated genetic groups that did only partly follow recent taxonomic concepts, but were strictly allopatric. While some of the previ- ously described taxa constitute distinct genetic entities, others have no taxonomic value. Synthesizing our AFLP data with ploidy-level information obtained from all genetically investigated individuals as well as with chromosome counts revealed that tetraploid individuals prevail, while octoploids occur only within S. filifolia. Lack of AFLP divergence between tetra- and octoploids suggests an autopolyploid origin of the latter. The genetic differentiation pattern was reflected by morphological differentiation, allowing for a taxonomic revision of the constituents of S. rigida sensu Fl. Eur. resulting in recognition of the four species S. achtarovii, S. filifolia, S. rigida, and S. serbica.

Epidendrum (Orchidaceae) as a model system for ecological and evolutionary studies in the Neotropics

Abstract: The orchid genus Epidendrum, with 1500 species occurring within the Neotropical region, represents a very promising model system for evolutionary and ecological studies offering an expanded repertoire of research opportunities in the breadth of modern plant biology. Epidendrum displays a significant degree of morphological variation, chromosome number diversity and ecological interactions, which challenges widely held views on reproductive barriers and habitat selection. The widespread geographical distribution of many species and populations offers interesting opportunities to investigate how climatic changes and historic demographic processes shaped the current patterns of genetic and species diversity across different biomes and landscapes. Questions involving chromosome barriers to gene exchange and the role of postzygotic genetic barriers in species cohesion (e.g., the contributions of habitat selection and niche divergence on species cohesion) could be easily addressed when using the variety of natural hybrid zones found across Epidendrum. Several key evolutionary questions could be addressed with this model system, such as the identification of the first stages of adaptive radiation, the evolution of pollination strate- gies, the adaptive ecological significance of trait variation and hybridisation, the influence of historical demographic events on lineage diversification and speciation. With the advance of cost-effective molecular techniques and by combining ecologi- cal and phenotypic data, researchers can now tackle these questions and foster significant progress in the field of Neotropical plant diversification and evolution.

Gymnaconitum, a new genus of Ranunculaceae endemic to the Qinghai-Tibetan Plateau

Abstract: The monophyly of traditional Aconitum remains unresolved, owing to the controversial systematic position and taxonomic treatment of the monotypic, Qinghai-Tibetan Plateau endemic A. subg. Gymnaconitum. In this study, we analyzed two datasets using maximum likelihood and Bayesian inference methods: (1) two markers (ITS, trnL-F) of 285 Delphinieae species, and (2) six markers (ITS, trnL-F, trnH-psbA, trnK-matK, trnS-trnG, rbcL) of 32 Delphinieae species. All our analyses show that traditional Aconitum is not monophyletic and that subgenus Gymnaconitum and a broadly defined Delphinium form a clade. The SOWH tests also reject the inclusion of subgenus Gymnaconitum in traditional Aconitum. Subgenus Gymnaconitum markedly differs from other species of Aconitum and other genera of tribe Delphinieae in many non-molecular characters. By integrating lines of evidence from molecular phylogeny, divergence times, morphology, and karyology, we raise the mono- typic A. subg. Gymnaconitum to gener ic status.

Molecular and morphological analysis of subfamily Alooideae (Asphodelaceae) and the inclusion of Chortolirion in Aloe

Abstract: Asphodelaceae subfam. Alooideae (Asparagales) currently comprises five genera, four of which are endemic to southern Africa. Despite their importance in commercial horticulture the evolutionary relationships among the genera are still incompletely understood. This study examines phylogenetic relationships in the subfamily using an expanded molecular sequence dataset from three plastid regions (matK, rbcLa, trnH-psbA) and the first subunit of the nuclear ribosomal internal transcribed spacer (ITS1). Sequence data were analysed using maximum parsimony and Bayesian statistics, and selected morphological traits were mapped onto the molecular phylogeny. Haworthia is confirmed as being polyphyletic, comprising three main clades that largely correlate with current subgeneric circumscriptions. Astroloba and Gasteria are evidently each monophyletic and sister respectively to Astroloba and H. subg. Robustipedunculares. Chortolirion is shown to be deeply nested within Aloe and is formally included in that genus. Aloe itself is clearly polyphyletic, with the dwarf species A. aristata allied to Haworthia subg. Robustipedunculares. The taxonomic implications of these findings are examined but branch support at critical lower nodes is insufficient at this stage to justify implementing major taxonomic changes.

A global infrageneric classification system for the genus Crotalaria (Leguminosae) based on molecular and morphological evidence

Abstract: Crotalaria is a large genus of 702 species with its centre of diversity in tropical Africa and Madagascar and secondary radiations in other parts of the world. The current infrageneric classification system is based on morphological and morphometric studies of the African taxa only and is here re-evaluated using a phylogenetic approach. DNA sequences derived from the nuclear ITS and the plastid matK, psbA-trnH and rbcLa markers were analyzed using parsimony and model-based (Bayesian) approaches. The resultant molecular phylogeny allowed for a new interpretation of diagnostically important morphological characters, including specialisations of the calyx, keel, standard petal and style, which are variously convergent in several unrelated infrageneric groups. Of particular interest is the congruence between the new phylogeny and the distribution of standard petal callosity types. A sectional classification system for the entire genus is proposed for the first time. The new system that is formalised here comprises eleven sections: Amphitrichae, Calycinae, Crotalaria, Geniculatae, Glaucae, Grandiflorae, Hedriocarpae, Incanae, Schizostigma, Borealigeniculatae and Stipulosae. Sectional limits of the Geniculatae, Calycinae and Crotalaria are modified. The subsections Stipulosae, Glaucae and Incanae are raised to sectional level, while some groups previously recognized as subsections are abandoned due to non-monophyly (subsections Chrysocalycinae, Hedriocarpae, Macrostachyae and Tetralobocalyx). Two new sections are recognized, Amphitrichae and Borealigeniculatae.

Molecular phylogeny and historical biogeography of the lichen-forming fungal genus Flavoparmelia (Ascomycota: Parmeliaceae)

Abstract: The lichen-forming fungal genus Flavoparmelia includes species with distinct distribution patterns, including subcos- mopolitan, restricted, and disjunct species. We used a dataset of nuclear ITS and LSU ribosomal DNA including 51 specimens to understand the influence of historical events on the current distribution patterns in the genus. We employed Bayesian, maxi- mum likelihood and maximum parsimony approaches for phylogenetic analyses, a likelihood-based approach to ancestral area reconstruction, and a Bayesian approach to estimate divergence times of major lineages within the genus. We identified two major clades in the genus, one of them separating into two subclades and one of those into four groups. Several of the groups and clades have restricted geographical ranges in the Southern Hemisphere, but two groups include species with wider distribution areas. Our analyses suggest that the genus originated in southern South America during the Eocene-Oligocene transition and that the diversification of the Australasian groups occurred recently. The subcosmopolitan distribution of species is explained by long-distance dispersal, while vicariance probably played a major role in the origin of the genus. Several currently accepted species were found to be non-monophyletic, indicating that the species delimitation in the genus requires further studies.

Molecular phylogenetics of Chelonopsis ( Lamiaceae: Gomphostemmateae) as inferred from nuclear and plastid DNA and morphology

Abstract: The recently established tribe Gomphostemmateae (Lamiaceae) consists of Gomphostemma, Bostrychanthera and Chelonopsis, but relationships within and between these genera have not been well studied. Only six of the approximately 46 species of Gomphostemmateae have been included in any previous phylogenetic analysis. In the present study, we used DNA sequences of two nuclear regions (ITS, ETS) and five plastid loci (psbA-trnH, rps 16, trnL intron, trnL-trnF spacer, trnStrnG) to reconstruct the phylogeny of the East Asian genus Chelonopsis for the first time. The molecular results indicate that the tribe Gomphostemmateae is monophyletic; Bostrychanthera is embedded in Chelonopsis; and Chelonopsis comprises two clades, one encompassing the taxa of Chelonopsis subg. Chelonopsis and the genus Bostrychanthera and the other consisting of Chelonopsis subg. Aequidens. This split is supported by several morphological characters. These results, which are further strengthened by morphological and cytological data, indicate that Bostrychanthera should be transferred to Chelonopsis. In addition, our results show that within C. subg. Aequidens, sect. Aequidens and sect. Microphyllum are monophyletic. Furthermore, two major clades are concordant with the Sino-Japanese and Sino-Himalayan distribution patterns..