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Taxonomy of Leguminosae

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Darien Eros Prado
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Protti Cosenza, L.; E. Moya, M. J. Franco, M. Brea & D. Prado. 2022. Anatomy of the wood and charcoal of Anadenanthera colubrina var. colubrina (Leguminosae, Caesalpinioideae). Darwiniana, nueva serie 10(1): 103-115. The aim of this paper was to carry out an anatomical description of the secondary xylem and charcoal of Anadenanthera colubrina var. colubrina (Leguminosae: Caesalpinioideae). This taxon mainly inhabits seasonally dry forests and it is a tree that has been part of the economic, medicinal, and spiritual development in South America. The samples were collected in Parque Urquiza, Paraná, Entre Ríos, Argentina. The wood was sectioned using a manual rotary microtome and the charcoals were obtained using a muffle at 400 °C for 40 minutes. A detailed description of the wood and charcoal of Anadenanthera colubrina var. colubrina, based on light microscopic and scanning electron microscopic observation, is presented. The results indicate the following diagnostic features: growth rings slightly distinct, diffuse-porous wood; mostly solitary vessels, rare in radial multiples of 2-4 elements and in clusters, simple perforation plates, intervessel pits alternate and vestured; axial parenchyma paratracheal, vasicentric and confluent, prismatic crystals in chambered axial parenchyma cells, rays 1-4 seriate, homocellular composed exclusively of procumbent cells. These detailed descriptions will facilitate the identification of Anadenanthera colubrina in archaeological and paleontological contexts.
Bente B. Klitgaard
added 7 research items
The need for scientists to exchange, share and organise data has resulted in a proliferation of biodiversity research-data portals over recent decades. These cyber-infrastructures have had a major impact on taxonomy and helped the discipline by allowing faster access to bibliographic information, biological and nomenclatural data, and specimen information. Several specialised portals aggregate particular data types for a large number of species, including legumes. Here, we argue that, despite access to such data-aggregation portals, a taxon-focused portal, curated by a community of researchers specialising on a particular taxonomic group and who have the interest, commitment, existing collaborative links, and knowledge necessary to ensure data quality, would be a useful resource in itself and make important contributions to more general data providers. Such an online species-information system focused on Leguminosae (Fabaceae) would serve useful functions in parallel to and different from international data-aggregation portals. We explore best practices for developing a legume-focused portal that would support data sharing, provide a better understanding of what data are available, missing, or erroneous, and, ultimately, facilitate cross-analyses and direct development of novel research. We present a history of legume-focused portals, survey existing data portals to evaluate what is available and which features are of most interest, and discuss how a legume-focused portal might be developed to respond to the needs of the legume-systematics research community and beyond. We propose taking full advantage of existing data sources, informatics tools and protocols to develop a scalable and interactive portal that will be used, contributed to, and fully supported by the legume-systematics community in the easiest manner possible.
This pre-print is currently under consideration at Molecular Ecology. Hybridization has the potential to generate or homogenize biodiversity and is a particularly common phenomenon in plants, with an estimated 25% of species undergoing inter-specific gene flow. However, hybridization in Amazonia’s megadiverse tree flora was assumed to be extremely rare despite extensive sympatry between closely related species, and its role in diversification remains enigmatic because it has not yet been examined empirically. Using members of a dominant Amazonian tree family (Brownea, Fabaceae) as a model to address this knowledge gap, our study recovered extensive evidence of hybridization among multiple lineages across phylogenetic scales. More specifically, our results uncovered several historical introgression events between Brownea lineages and indicated that gene tree incongruence in Brownea is best explained by introgression, rather than solely by incomplete lineage sorting. Furthermore, investigation of recent hybridization using ~19,000 ddRAD loci recovered a high degree of shared variation between two Brownea species which co-occur in the Ecuadorian Amazon. Our analyses also showed that these sympatric lineages exhibit homogeneous rates of introgression among loci relative to the genome-wide average, implying a lack of selection against hybrid genotypes and a persistence of hybridization over time. Our results demonstrate that gene flow between multiple Amazonian tree species has occurred across temporal scales, and contrasts with the prevailing view of hybridization’s rarity in Amazonia. Overall, our results provide novel evidence that reticulate evolution influenced diversification in part of the Amazonian tree flora, which is the most diverse on Earth.
Bente B. Klitgaard
added a research item
The urge to organise the world around us is an essential part of human nature. Naming and categorising enable us to store and access information ef ciently. The need to name and categorise extends to the natural world and, in particular, to living organisms. The science underpinning this area of knowledge is called Taxonomy, and is as old as humanity itself. Although humans have studied natural phenomena and organisms since the time of the ancient Greeks and Romans, the latter half of the 20th century saw scientists increasingly focused on determining the number of species on the planet, in other words, quantifying global biodiversity. Two hundred years earlier, the Swedish naturalist Carolus Linnaeus had transformed biological classi cation by establishing binomial nomenclature, the starting point for modern biological taxonomy. Medical doctors and naturalists, followed by generations of biologists, botanists, zoologists, microbiologists and mycologists all over the world went on to describe the living organisms which collectively comprise earth’s biodiversity. A necessidade de organizar o mundo ao nosso redor constitui parte essencial da natureza humana. Dar nomes e organizar em categorias nos permite armazenar múltiplas informações e acessá-las de forma eficiente. Essa necessidade certamente inclui elementos da natureza e os seres vivos em particular. A ciência responsável por esta área do conhecimento, no que diz respeito aos seres vivos, chama-se Taxonomia e ela é tão antiga quanto a própria humanidade. Embora os organismos e fenômenos da natureza sejam estudados desde o tempo dos antigos Gregos e Romanos, foi a partir da segunda metade do século XX que os cientistas aumentaram o foco na deter-minação de qual seria o número total de espécies no planeta ou, em outras palavras, qual a biodiversi-dade da Terra. Já haviam se passado mais de 200 anos desde que o naturalista sueco Carolus Linnaeus, havia sistematizado a classificação biológica, por meio da nomenclatura binomial, criando assim a Taxonomia biológica moderna. Inicialmente médicos e naturalistas e, posteriormente, biólogos, botânicos, zoólogos, microbiologistas e micologistas passaram a descrever os seres vivos componentes da biodiversidade.
Darien Eros Prado
added a research item
Backgrounds and aims: The genus Anadenanthera is represented in Argentina by a single species, A. colubrina, with two varieties var. cebil and var. colubrina. These varieties can be clearly distinguished by the venation pattern of the leaflets. In this work a third variety, var. glabra, is here circumscribed by a combination of characters of its leaves and bark. M&M: Specimens at CTES and MCNS were studied, and field observations were performed in Argentinean natural environments. The specimens were analyzed morphologically with optical and scanning electron microscopies. Results: The new variety glabra differs from varieties cebil and colubrina by its stems without mamelons, leaves with rachis glabrous on both surfaces or only on the abaxial surface, and leaflets with a reticulated, closed and complex venation. An illustration, photographs, a morphological comparative table, a key to the varieties, and a distribution map are provided. Conclusions: The three varieties of Anadenanthera colubrina, var. cebil, var. colubrina and var. glabra, inhabit the Seasonally Dry Neotropical Forests of northern Argentina, showing the new variety a restricted distribution to the northeastern region of the country.
Ashley N Egan
added a research item
The Advances in Legume Systematics (ALS) series has provided the venues for publishing outputs from the series of seven International Legume Conferences (ILC) held over the last four decades. The first two editions arising from the first ILC in 1978 at the Royal Botanic Gardens, Kew, were published in 1981. The first ten parts of ALS were published as a coherent series by the Royal Botanic Gardens, Kew Publishing, whereas more recent editions have been published as Special Issues of botanical journals – Part 11 in Australian Systematic Botany in 2003, and Part 12 in the South African Journal of Botany in 2013. This, the 13th edition of the ALS series, is here published as a Special Issue of Australian Systematic Botany, and includes papers arising from the 7th ILC held in Sendai, Japan, in September 2018. The ALS13 Special Issue includes a potpourri of papers spanning the full spectrum of topics and research activities in current legume systematics, namely fossils, morphology, classification and taxonomy, ethnobotany, genomics and informatics.
Darien Eros Prado
added a research item
The Gran Chaco is a wide ecologic-geographic region comprising northern Argentina, western Paraguay, southern Bolivia and the southwestern extreme of Brazil. This region exhibits extreme temperatures, annually regular frosts, and sedimentary soils; it has been dramatically threatened by agriculture expansion in recent decades. Therefore, increasing knowledge of plant diversity is critical for conservation purposes. We present a Legume checklist of the Gran Chaco ecoregion including conservation status of its endemic species. Leguminosae is the third most diverse plant family in the Neotropics. Assuming a rigorous spatial definition of the Gran Chaco, we recorded 98 genera, 362 species, and 404 specific and infraspecific taxa. Endemic/typical taxa were 17%, comparable to adjacent tropical plant formations, and they were found in higher percentages in Caesalpinioideae (24%) and Cercidoideae (33%) than Papilionoideae (11%) subfamily. We also analyzed the plant diversity comparing lineages and subregions. The Gran Chaco Legumes are predominantly widespread generalists, or they belong to either Chaco sensu stricto or Neotropical Seasonally Dry Tropical Forest (SDTF) lineages. Though the Humid Chaco registered the highest species richness, Dry Chaco and Sierra Chaco, the most threatrened subregions, exhibited the highest percentages of exclusive and proper Chaco-lineage species. These results suggest that diversification of Legumes has been most relevant in Dry Chaco and Sierra Chaco, probably by their more demanding and harsh environmental conditions limiting the dispersion of generalists or intrusive-invading species. This study is paramount to reach an improved delimitation of the Gran Chaco ecoregion in transitional areas with the SDTF and Cerrado formations. Conservation status is critical in genera of high economic interest, such as Arachis, Mimosa and Prosopis. At least one third of endemic taxa exhibit a critical status of conservation or are endangered, many of them being relevant to inbreeding program or exhibiting multiple economic uses.
Bente B. Klitgaard
added a research item
The need for scientists to exchange, share, and organise data has resulted in a proliferation of research data portals in the past decades. These cyberinfrastructures have had a major impact on taxonomy and helped to revitalise the discipline, by allowing quick access to bibliographic information, biological and nomenclatural data, and specimen information. In addition, several specialised portals aggregate particular data types for a large number of species and can be queried to extract information for a particular taxonomic group. Because of their ecological and economic importance, several early initiatives to develop and deploy information technologies for capturing, sharing, and disseminating information focused specifically on the plant family Leguminosae (Fabaceae). Initiatives such as ILDIS (International Legume Database and Information Service), which was created in 1985, led the way in developing methods and thinking with regard to taxonomic data management more generally. More recently, the Legume Phylogeny Working Group (LPWG) was founded in 2010 with the objective of facilitating collaboration amongst systematists working on the plant family Leguminosae (Fabaceae). As part of this endeavour, the LPWG has explored whether it would be desirable and pertinent to develop a new portal focused on the legume family. We argue that, despite access to numerous data aggregation portals, a taxon-focussed portal curated by a community of researchers specialised on a particular taxonomic group, such as the LPWG, have the interest, commitment, existing collaborative links, and knowledge necessary to verify data quality, thereby providing a valuable resource and actively contributing to other more general data providers. We consider that a new portal focused on Leguminosae would thus serve a useful function in parallel to and different from large international data-aggregation portals. We explored best practices for developing a legume-focused portal that will enable long-term sustainability, data sharing, a better understanding of what data are available, missing, or erroneous, and ultimately facilitate cross analyses and development of novel research. We surveyed existing data portals to see what features are of interest to our goal and we present a general way forward for developing a legume-focused portal that would respond to the needs of the legume systematics research community as well as to the broader user community. We propose to take full advantage of existing data sources, informatics tools, and protocols to develop an easily manageable, scalable, and interactive portal that will be used, contributed to, and fully endorsed and supported by the legume systematics community.
Bente B. Klitgaard
added 2 research items
The following legume genera in Ecuador are revised: Cajanus (1 sp.), Calopogonium (3 spp.), Centrosema (9 spp.), Cologania (1 sp.), Galactia (2 spp.), Mucuna (8 spp.), Pueraria (1 sp.), Rhynchosia (7 spp.) and Teramnus (2 spp.). The especies of Cajanus and Pueraria, C. cajan and P. phaseoloides, originate from Asia and have become established in seminatural, disturbed habitats. One new species, Mucuna ecuatoriana, is described and several lectotypifications are made. Keys to all species are presented within respective genus along with synonymy, speciemen citations, taxonomic references, and information on ecology and distribution. Many species are illustrated with either line drawings and/or colour photos.
Bente B. Klitgaard
added a research item
Detarioideae (81 genera, c. 760 species) is one of the six Leguminosae subfamilies recently reinstated by the Legume Phylogeny Working Group. This subfamily displays high morphological variability and is one of the early branching clades in the evolution of legumes. Using previously published and newly generated sequences from four loci (matK-trnK, rpL16, trnG-trnG2G and ITS), we develop a new densely sampled phylogeny to assess generic relationships and tribal delimitations within Detarioideae. The ITS phylogenetic trees are poorly resolved, but the plastid data recover several strongly supported clades, which also are supported in a concatenated plastid + ITS sequence analysis. We propose a new phylogeny-based tribal classification for Detarioideae that includes six tribes: re-circumscribed Detarieae and Amherstieae, and the four new tribes Afzelieae, Barnebydendreae, Saraceae and Schotieae. An identification key and descriptions for each of the tribes are also provided.
Bente B. Klitgaard
added a research item
The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near-complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well-supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community-endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or clade-based classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.
Bente B. Klitgaard
added a research item
First-prize winning poster, which was presented at Imperial College London Life Sciences PhD poster session. This poster details the work undertaken for the first section of this PhD project, investigating the phylogenetic relationships, pace of evolution over time and biogeographical history of the Brownea clade.
Bente B. Klitgaard
added 2 research items
Aspects of the pollination ecology of Browneopsis disepala, including floral scent composition, were studied. Floral scent was collected with head space techniques and analyzed by coupled gas chromatography-mass spectrometry. Inflorescence and flower development were followed, and amount and concentration of nectar measured. Flower-visiting animals were observed nocturally and diurnally. Inflorescences of B. disepala emit a floral scent that is typical of neither moth- nor bat-pollinated plants, but contains some compounds related to both pollination types. Nectar is produced in quantities and with sugar concentrations falling within a range typical of both moth- and bat-pollinated plants. The inflorescences are visited by both moths and bats, but the behavior of the bats suggests that they are the more efficient pollinators. Browneopsis disepala has a mixed pollination system and is dependent on animals for pollination.
Bente B. Klitgaard
added 2 research items
The Fabales clade comprises four families: Leguminosae, Polygalaceae, Quillajaceae and Surianaceae. This study presents new information on the pollen morphology of Quillaja, the only genus of Quillajaceae, and Recchia, Guilfoylia, Cadellia, Suriana and Stylobasium, the five genera that comprise Surianaceae. The pollen of 9 of the 11 species currently recognised within the two families was examined using light microscopy (LM), scanning electron microscopy (SEM) and, selectively, with transmission electron microscopy (TEM). Pollen of all taxa is isopolar with tri-zonocolporate apertures, lalongate endoapertures with fastigia adjacent to the endoaperture, and long ectoapertures that are nearly equal to the polar length. Apocolpia are correspondingly small. Quillaja pollen is subprolate to prolate, and striate with a granular aperture surface membrane. Ectexine protrudes over the endoapertures. In thin section the foot layer is thicker in mesocolpial areas and thin to discontinuous around the apertures, where the endexine is thicker. Cadellia pollen is prolate spheroidal, and striate with a granular aperture surface membrane. Exine protrudes over the endoapertures. In thin section the endexine is thicker and lamellate around the endoaperture area, and the foot layer is thicker in mesocolpial regions. Guilfoylia pollen is oblate and gemmate-verrucate, with a granular aperture surface membrane. Columellae are short. Recchia pollen is suboblate to oblate spheroidal, and microreticulate-perforate with a granular aperture surface membrane. Exine protrudes over the endoapertures. The foot layer is thin to discontinuous around aperture margins and thick in mesocolpial regions. Stylobasium pollen is suboblate, and finely rugulate-perforate with a granular aperture surface membrane. Columellae are short, the foot layer is thin or absent. Suriana pollen is suboblate, and finely rugulate-perforate with a granular aperture surface membrane. Pollen of Cadellia and Recchia, and Stylobasium and Suriana are morphologically similar. Verrucate surface ornamentation is only present in Guilfoylia. Quillaja, Cadellia and Recchia share the character of protruding exine over the endoaperture area. Striate ornamentation occurs in Quillaja and Cadellia. The pollen morphology of Quillajaceae has more in common with that of Leguminosae and Surianaceae, and with Cadellia in particular, than with Polygalaceae.
Recent studies have shown that Acacia is polyphyletic and must be split into five genera. Proposal 1584 would retypify Acacia : the type of the Australian taxon A. penninervis would be conserved over the current lectotype ( A. scorpioides ) of an African taxon. We disagree with the recommendation of the Spermatophyte Committee to endorse this proposal. Contrary to Article 14.12 of the ICBN, no detailed case against conservation was presented in Proposal 1584. We maintain that there are strong arguments against conservation, such as the large number of countries that would be affected, the economic importance of the extra-Australian species, and the economic burden placed on developing countries. Acceptance of this proposal would also violate the guidelines for conservation which clearly state that the principle of priority should prevail when conservation for one part of the world would create disadvantageous change in another part of the world.
Bente B. Klitgaard
added 9 research items
The phylogenetic affinities of the aberrant monotypic genus Duparquetia (subfamily Caesalpinioideae) are at present unresolved. Preliminary results from molecular analyses suggest a basal, isolated position among legumes. A study of Duparquetia pollen was carried out to provide further morphological characters to contribute to multi-data set analyses. Understanding the development of Duparquetia pollen was necessary to clarify the orientation of the apertures. Pollen grains and developing microspores were examined using light microscopy, confocal microscopy and scanning electron microscopy. Evidence for the orientation of the apertures was provided by the examination of microspores within developing tetrads, using (a) confocal microscopy to locate the position of the ectoapertures, and (b) light microscopy and Alcian blue stain to locate the position of the endoapertures. Confocal microscopy has been used for the first time to examine developing microspores in order to obtain information on ectoapertures that was unavailable using other techniques. Pollen in Duparquetia develops in tetrahedral tetrads as in other eudicots, with the apertures arranged in a modified pattern following Fischer's rule. Pollen grains are asymmetrical and have one equatorial-encircling ectoaperture with two equatorial endoapertures, a unique feature in Leguminosae, and in eudicots. The pollen morphology of Duparquetia is so unusual that it provides little information to help determine its closest relatives. However, it does fit with a pattern of greater pollen morphological diversity in the first-branching caesalpinioid legume groups than in the more derived clades. The latitudinal ectoaperture of Duparquetia is unique within the Fabales and eudicot clades, resembling more closely the monosulcate pollen found in monocots and basal angiosperms; however, developmental patterns are recognizably similar to those of all other legume pollen types.
Duparquetia orchidacea (Caesalpinioideae-Cassieae-Duparquetiinae) is a monotypic liana from tropical West Africa. Its highly unusual, zygomorphic flowers, the unique pollen morphology, and the lack of vestured pits in the wood correspond with previous phylogenetic studies that resolved the position of the species to an isolated position among the early-branching Leguminosae. Here we present a detailed analysis of floral morphology and development to clarify open questions of its floral organization. We provide new data that can be useful in clarifying phylogenetic relationships among early branching Leguminosae and improve our understanding of floral evolution in this large and important plant family. For comparison, we also present developmental data for other Fabales. Our analysis reveals some unusual and in parts unique developmental patterns, such as strict acropetal organ formation, loss and suppression of floral organs, and early petal enlargement. We interpret alternating left-right symmetries in floral development as clues to a spiral organ formation in ancestral taxa. Early asymmetry of the young carpel helps to interpret enantiostyly of other Leguminosae as an example of imprinted shape. Finally, we show that cochlear-descending petal aestivation in Duparquetia and in Papilionoideae is based on different ontogenetic patterns and therefore is most probably nonhomologous.
An overview of pollen morphology from all genera in the family Polygalaceae is presented to assist systematic studies of the Fabales clade. The pollen of 72 species, representing 18 genera, in Polygalaceae was examined using light microscopy and scanning electron microscopy. In addition, the pollen of eight species, representing seven genera, was examined using transmission electron microscopy. Pollen is described and illustrated for each genus, and the first pollen descriptions and publication of photomicrographs are presented for seven genera: Balgoya, Barnhartia, Comesperma, Diclidanthera, Eriandra, Moutabea, plus Polygala subgenus Badiera, and species previously included in Nylandtia (now in Muraltia). Pollen morphological similarities and differences broadly correspond with relationships suggested by recent molecular phylogenies. The aperture number was also found to correlate with trees generated using molecular data; early branching taxa have lower aperture numbers than later branching ones. The overall range of ectoaperture numbers seen in Polygalaceae, excluding Balgoya, is between five and 33. The pollen of Balgoya is tricolporate; all other genera have pollen with a range of ectoaperture numbers within each sample. The degree of endoaperture fusion to form endocingula is variable at a subgeneric level. All pollen is isopolar, except for that of Heterosamara and Polygala wattersii. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 156, 253–289.
Bente B. Klitgaard
added 4 research items
Closer collaboration among ecologists, systematists, and evolutionary biologists working in tropical forests, centred on studies within long-term permanent plots, would be highly beneficial for their respective fields. With a key unifying theme of the importance of vouchered collection and precise identification of species, especially rare ones, we identify four priority areas where improving links between these communities could achieve significant progress in biodiversity and conservation science: (i) increasing the pace of species discovery; (ii) documenting species turnover across space and time; (iii) improving models of ecosystem change; and (iv) understanding the evolutionary assembly of communities and biomes.
Abstract: Four species of Brownea are used medically to treat "diseases" related to the blood: for birth control, menstruation and wound healing, by indigenous people of Guyana, Venezuela, Colombia, Ecuador, and Peru. The use has been established based on literature search, botanical collactions labels, and information obtained from the Siona-Secoya and Quichua Indians in Ecuador. Possible explanations for their application and economic potential are discussed. Resumen: Cuatro especie de Brownea son utilizadas medicinalmente para el tratamiento de "enfermedades" relacionadas con le "sangre"; como anticonceptivos; para menstruación y cicatrización, por los indígenas de Guyana, Venezuela, Colombia, Ecuador y Peru. Los usos presentados se han basado en la bibliografía, datos de las etiquetas re recolecciones botánicas y la información obtenida de los indígenas Siona-secoya y Quichua en Ecuador. Se discuten posibles explicaciones para sus usos y su potencial económino.
Darien Eros Prado
added a research item
The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near-complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well-supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community-endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or cladebased classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.
Darien Eros Prado
added 40 research items
This study puts together genetic data and an approximate bayesian computation (ABC) approach to infer the time at which the tree Geoffroea spinosa colonized the Galápagos Islands. The genetic diversity and differentiation between Peru and Galápagos population samples, estimated using three chloroplast spacers and six microsatellite loci, reveal significant differences between two mainland regions separated by the Andes mountains (Inter Andean vs. Pacific Coast) as well as a significant genetic differentiation of island populations. Microsatellites identify two distinct geographical clusters, the Galápagos and the mainland, and chloroplast markers show a private haplotype in the Galápagos. The nuclear distinctiveness of the Inter Andean populations suggests current restricted pollen flow, but chloroplast points to cross-Andean dispersals via seeds, indicating that the Andes might not be an effective biogeographical barrier. The ABC analyses clearly point to the colonization of the Galápagos within the last 160,000 years and possibly as recently as 4750 years ago (475 generations). Founder events associated with colonization of the two islands where the species occurs are detected, with Española having been colonized after Floreana. We discuss two nonmutually exclusive possibilities for the colonization of the Galápagos, recent natural dispersal vs. human introduction.