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Leaf spectra, trait data, and phylogenies for plant species collected by the Canadian Airborne Biodiversity Observatory (CABO).

See 'Read me.rtf' (included in 'Data S1.rar') for a description of the files included in this dataset. Abstract of study: Early natural historians – Comte de Buffon, von Humboldt and De Candolle – established environment and geography as two principal axes determining the distribution of groups of organisms, laying the foundations for biogeography over the subsequent 200 years, yet the relative importance of these two axes remains unresolved. Leveraging phylogenomic and global species distribution data for Mimosoid legumes, a pantropical plant clade of c. 3,500 species, we show that the water availability gradient from deserts to rainforests dictates turnover of lineages within continents across the tropics. We demonstrate that 95% of speciation occurs within a precipitation niche, showing profound phylogenetic niche conservatism, and that lineage turnover boundaries coincide with isohyets of precipitation. We reveal similar patterns on different continents, implying that evolution and dispersal follow universal processes.

PREMISE Pollinators are thought to exert selective pressures on plants, mediating the evolution of convergent floral shape often recognized as pollination syndromes. However, little is known about the accuracy of using petal shape for inferring convergence in pollination mode without a priori pollination information. Here we studied the genus Erythrina L. as a test case to assess whether ornithophyllous pollination modes (hummingbirds, passerines, sunbirds, or mixed pollination) can be inferred based on the evolutionary analysis of petal shape. METHODS We characterized the two-dimensional dissected shape of standard, keel, and wing petals from 106 Erythrina species using geometric morphometrics and reconstructed a phylogenetic tree of 83 Erythrina species based on plastid trnL-F and nuclear ribosomal ITS sequences. We then used two phylogenetic comparative methods based on Ornstein-Uhlenbeck models, SURFACE and l1OU, to infer distinct morphological groups using petal shape and identify instances of convergent evolution. The effectiveness of these methods was evaluated by comparing the groups inferred to known pollinators. RESULTS We found significant petal shape differences between hummingbird- and passerine-pollinated Erythrina species. Our analyses also revealed that petal combinations generally provided better inferences of pollinator types than individual petals and that the method and optimization criterion can affect the results. CONCLUSIONS We show that model-based approaches using petal shape can detect convergent evolution of floral shape and relatively accurately infer pollination modes in Erythrina. The inference power of the keel petals argues for a deeper investigation of their role in the pollination biology of Erythrina and other bird-pollinated legumes.

SummaryPlant ecologists use functional traits to describe how plants respond to and influence their environment. Reflectance spectroscopy can provide rapid, non-destructive estimates of leaf traits, but it remains unclear whether general trait-spectra models can yield accurate estimates across functional groups and ecosystems.We measured leaf spectra and 22 structural and chemical traits for nearly 2000 samples from 104 species. These samples span a large share of known trait variation and represent several functional groups and ecosystems. We used partial least-squares regression (PLSR) to build empirical models for estimating traits from spectra.Within the dataset, our PLSR models predicted traits like leaf mass per area (LMA) and leaf dry matter content (LDMC) with high accuracy (R2>0.85; %RMSER2=0.55-0.85; %RMSE=12.7-19.1). Micronutrients such as Cu and Fe showed the poorest accuracy. In validation on external datasets, models for traits like LMA and LDMC performed relatively well, while carbon fractions showed steep declines in accuracy.We provide models that produce fast, reliable estimates of several widely used functional traits from leaf reflectance spectra. Our results reinforce the potential uses of spectroscopy in monitoring plant function around the world.

Early natural historians – Compte de Buffon, von Humboldt and De Candolle – established ecology and geography as two principal axes determining the distribution of groups of organisms, laying the foundations for biogeography over the subsequent 200 years, yet the relative importance of these two axes remains unresolved. Leveraging phylogenomic and global species distribution data for Mimosoid legumes, an pantropical plant clade of 3,400 species, we show that the water availability gradient from deserts to rainforests dictates turnover of lineages within continents across the tropics. We demonstrate that 95% of speciation occurs within a precipitation niche, showing profound phylogenetic niche conservatism, and that lineage turnover boundaries coincide with isohyets of precipitation. We reveal similar patterns on different continents, implying that evolution and dispersal follow universal processes. Fil: Ringelberg, Jens J. University of Zurich. Department of Systematic and Evolutionary Botany; Suiza Fil: Koenen, Erik J.M. University of Zurich. Department of Systematic and Evolutionary Botany; Suiza. Université Libre de Bruxelles. Faculté des Sciences. Evolutionary Biology & Ecology; Bélgica Fil: Sauter, Benjamín. University of Zurich. Department of Systematic and Evolutionary Botany; Suiza Fil: Aebli, Anahita. University of Zurich. Department of Systematic and Evolutionary Botany; Suiza. Abteling Umweltschutz und Energie. Departement Bau und Umwelt; Suiza Fil: Rando, Juliana G. Universidade Federal do Oeste da Bahia. Centro das Ciências Biológicas e da Saúde. Programa de Pós Graduação em Ciências Ambientais; Brasil Fil: Iganci, João R. Universidade Federal de Pelotas. Campus Universitário Capão do Leão. Instituto de Biologia; Brasil. Universidade Federal do Rio Grande do Sul. Programa de Pós-Graduação em Botânica; Brasil Fil: de Queiroz, Luciano P. Universidade Estadual de Feira de Santana. Departamento Ciências Biológicas; Brasil Fil: Murphy, Daniel J. Royal Botanic Gardens Victoria: Australia Fil: Gaudeul, Myriam. Institut de Systématique, Evolution, Biodiversité (ISYEB), MNHN-CNRS-SU-EPHE-UA: Francia Fil: Bruneau, Anne. Université de Montréal. Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques; Canadá Fil: Luckow, Melissa. Cornell University. School of Integrative Plant Science. Plant Biology Section; Estados Unidos Fil: Morales, Matias. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina

Phylogenomic analyses have helped resolve many recalcitrant relationships in the angiosperm tree of life, yet phylogenetic resolution of the backbone of the Leguminosae, one of the largest and most economically and ecologically important families, remains poor due to generally limited molecular data and incomplete taxon sampling of previous studies. Here, we resolve many of the Leguminosae’s thorniest nodes through comprehensive analysis of plastome-scale data using multiple modified coding and noncoding data sets of 187 species representing almost all major clades of the family. Additionally, we thoroughly characterize conflicting phylogenomic signal across the plastome in light of the family’s complex history of plastome evolution. Most analyses produced largely congruent topologies with strong statistical support and provided strong support for resolution of some long-controversial deep relationships among the early diverging lineages of the subfamilies Caesalpinioideae and Papilionoideae. The robust phylogenetic backbone reconstructed in this study establishes a framework for future studies on legume classification, evolution, and diversification. However, conflicting phylogenetic signal was detected and quantified at several key nodes that prevent the confident resolution of these nodes using plastome data alone. [Leguminosae; maximum likelihood; phylogenetic conflict; plastome; recalcitrant relationships; stochasticity; systematic error.]

Reticulation, caused by hybridization and allopolyploidization, is considered an important and frequent phenomenon in the evolution of numerous plant lineages. Although both processes represent important driving forces of evolution, they are mostly ignored in phylogenetic studies involving a large number of species. Indeed only a scattering of methods exists to recover a comprehensive reticulated evolutionary history for a broad taxon sampling. Among these methods, comparisons of topologies obtained from plastid markers with those from a few nuclear sequences are favored, even though they restrict in-depth studies of hybridization and polyploidization. The genus Rosa encompasses c. 150 species widely distributed throughout the northern hemisphere and represents a challenging taxonomic group in which hybridization and polyploidization are prominent. Our main objective was to develop a general framework that would take patterns of reticulation into account in the study of the phylogenetic relationships among Rosa species. Using amplicon sequencing, we targeted allele variation in the nuclear genome as well as haploid sequences in the chloroplast genome. We successfully recovered robust plastid and nuclear phylogenies and performed in-depth tests for several scenarios of hybridization using a maximum pseudo-likelihood approach on taxon subsets. Our diploid-first approach followed by hybrid and polyploid grafting resolved most of the evolutionary relationships among Rosa subgenera, sections, and selected species. Based on these results, we provide new directions for a future revision of the infrageneric classification in Rosa. The stepwise strategy proposed here can be used to reconstruct the phylogenetic relationships of other challenging taxonomic groups with large numbers of hybrid and polyploid taxa. [Amplicon sequencing; interspecific hybridization; polyploid detection; reticulate evolution.]

Astragalus, a highly diverse genus of flowering plants with its highest center of diversity in West Asia, is a classic example of rapid species-level radiation and adaptation to a diversity of habitats throughout the world. We examined the historical biogeography of Astragalus using molecular dating and ancestral area reconstruction to understand how past climate changes, geographical patterns and transition in life history have provoked diversification of Astragalus. Our results suggest that Astragalus probably originated during the middle Miocene in West Asia, underwent rapid diversification, subsequently and repeatedly expanded its range in the Mediterranean region, and later to North America through West Europe. This distribution range was also extended toward central and eastern Asia from the Middle Miocene to Pleistocene. Several climatic and geological processes during the Miocene-Pliocene may be implicated in the diversification of the major Astragalus clades. In particular, the annual lineages, which are important elements in the Mediterranean flora of Africa and Europe and in the deserts of southwest to central Asia, have arisen in response to progressing aridity from the late Miocene onwards (between 8.6 Ma and 2.98 Ma). Diversification rate analyses indicate three rapid and recent diversification events, one at c. 11 Ma in the clade that groups most of the Astragalus s.s. (all except the Ophiocarpus sister lineage), one at c. 5 Ma in the crown group of the Hypoglottis clade, including herbaceous annual and perennial species, and the most recent one at c. 3 Ma in the spiny cushion forming Astracantha clade. Our study highlights the complexity of processes and factors shaping diversifications in Astragalus; a complex interaction among climatic modifications providing opportunities for diversification and likely coincident with the evolution of key morphological and physiological adaptations.

The extent to which phylogenetic biome conservatism vs biome shifting determines global patterns of biodiversity remains poorly understood. To address this question, we investigated the biogeography and trajectories of biome and growth form evolution across the Caesalpinia Group (Leguminosae), a clade of 225 species of trees, shrubs and lianas distributed across the Rainforest, Succulent, Temperate and Savanna Biomes. We focused especially on the little-known Succulent Biome, an assemblage of succulent-rich, grass-poor, seasonally dry tropical vegetation distributed disjunctly across the Neotropics, Africa, Arabia and Madagascar. We reconstructed a time-calibrated phylogeny, assembled species occurrence data and assigned species to areas, biomes and growth forms. These data are used to estimate the frequency of transcontinental disjunctions, biome shifts and evolutionary transitions between growth forms and test for phylogenetic biome conservatism and correlated evolution of growth forms and biome shifts. We uncovered a pattern of strong phylogenetic Succulent Biome conservatism. We showed that transcontinental disjunctions confined within the Succulent Biome are frequent and that biome shifts to the Savanna, Rainforest and Temperate Biomes are infrequent and closely associated with shifts in plant growth forms. Our results suggest that the Succulent Biome comprises an ecologically constrained evolutionary arena spanning large geographical disjunctions across the tropics.

The consequences of the Cretaceous–Paleogene (K–Pg) boundary (KPB) mass extinction for the evolution of plant diversity remain poorly understood, even though evolutionary turnover of plant lineages at the KPB is central to understanding assembly of the Cenozoic biota. The apparent concentration of whole genome duplication (WGD) events around the KPB may have played a role in survival and subsequent diversification of plant lineages. To gain new insights into the origins of Cenozoic biodiversity, we examine the origin and early evolution of the globally diverse legume family (Leguminosae or Fabaceae). Legumes are ecologically (co-)dominant across many vegetation types, and the fossil record suggests that they rose to such prominence after the KPB in parallel with several well-studied animal clades including Placentalia and Neoaves. Furthermore, multiple WGD events are hypothesized to have occurred early in legume evolution. Using a recently inferred phylogenomic framework, we investigate the placement of WGDs during early legume evolution using gene tree reconciliation methods, gene count data and phylogenetic supernetwork reconstruction. Using 20 fossil calibrations we estimate a revised timeline of legume evolution based on 36 nuclear genes selected as informative and evolving in an approximately clock-like fashion. To establish the timing of WGDs we also date duplication nodes in gene trees. Results suggest either a pan-legume WGD event on the stem lineage of the family, or an allopolyploid event involving (some of) the earliest lineages within the crown group, with additional nested WGDs subtending subfamilies Papilionoideae and Detarioideae. Gene tree reconciliation methods that do not account for allopolyploidy may be misleading in inferring an earlier WGD event at the time of divergence of the two parental lineages of the polyploid, suggesting that the allopolyploid scenario is more likely. We show that the crown age of the legumes dates to the Maastrichtian or early Paleocene and that, apart from the Detarioideae WGD, paleopolyploidy occurred close to the KPB. We conclude that the early evolution of the legumes followed a complex history, in which multiple auto- and/or allopolyploidy events coincided with rapid diversification and in association with the mass extinction event at the KPB, ultimately underpinning the evolutionary success of the Leguminosae in the Cenozoic. [Allopolyploidy; Cretaceous–Paleogene (K–Pg) boundary; Fabaceae, Leguminosae; paleopolyploidy; phylogenomics; whole genome duplication events], info:eu-repo/semantics/published

Taxonomic names are critical to the communication of biodiversity—they link data together whether it be distribution data, traits or phylogeny. Large taxonomic groups, such as many plant families, are globally distributed as is the taxonomic expertise of the family. A growing knowledge base requires collaboration to develop an up-to-date checklist as a research foundation. The legume (Fabaceae) community has a strong history of collaboration including the International Legume Database and Information Service (ILDIS), which curated the names but ILDIS is no longer up to date. In 2020, under the umbrella of the Legume Phylogeny Working Group (LPWG), a group of taxonomists began updating the legume taxonomy as part of a larger collaboration around a legume data portal. Currently the World Checklist of Vascular Plants (WCVP) is the most up-to-date reference and was used as the starting point for the project. The workflow begins with over 80 volunteer taxonomic experts updating the checklist in their specialty area. These lists are manually collated, centrally creating a consensus taxonomy with synonyms. Any taxonomic conflicts are adjudicated within the group. The checklist then undergoes a comprehensive nomenclature assessment at Royal Botanic Gardens, Kew and becomes part of the WCVP. This checklist was submitted to the Catalogue of Life Checklist Bank and is integrated as the preferred legume checklist in the GBIF taxonomic backbone. After one round of taxonomic curation, 38% of the legume names in GBIF (Global Biodiversity Information Facility), which were previously unmatched to WCVP, are now connected to GBIF names, therefore also improving the occurrence records of those species. The GBIF taxonomic backbone contains names found on herbarium specimens and in the literature, which are not currently part of the legume expert community checklist or WCVP. This list of unresolved names will be forwarded to the legume community for curation, thereby developing a cycle of data improvement. It is anticipated that after a few rounds of expert curation, the WCVP and GBIF taxonomies will converge. At each cycle, a snapshot of GBIF occurrences is taken and the improvement of the occurrences is quantified to measure the value of the expert taxonomic work. The current checklist is also available via Catalogue of Life and soon via the World Flora Online to support research. In this talk, we describe the workflow and impact of the expert curated legume taxonomy.

Although often not collected specifically for the purposes of conservation, herbarium specimens offer sufficient information to reconstruct parameters that are needed to designate a species as 'at-risk' of extinction. While such designations should prompt quick and efficient legal action towards species recovery, such action often lags far behind and is mired in bureaucratic procedure. The increase in online digitization of natural history collections has now led to a surge in the number new studies on the uses of machine learning. These repositories of species occurrences are now equipped with advances that allow for the identification of rare species. The increase in attention devoted to estimating the scope and severity of the threats that lead to the decline of such species will increase our ability to mitigate these threats and reverse the declines, overcoming a current barrier to the recovery of many threatened plant species. Thus far, collected specimens have been used to fill gaps in systematics, range extent, and past genetic diversity. We find that they also offer material with which it is possible to foster species recovery, ecosystem restoration, and de-extinction, and these elements should be used in conjunction with machine learning and citizen science initiatives to mobilize as large a force as possible to counter current extinction trends.

Drawing upon the data deposited in publicly shared archives has the potential to transform the way we conduct ecological research. For this transformation to happen, we argue that data need to be more interoperable and easier to discover. One way to achieve these goals is to adopt domain-specific data representations.

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 recircum-scribed 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.

Detarioideae is well known for its high diversity of floral traits, including flower symmetry, number of organs, and petal size and morphology. This diversity has been characterized and studied at higher taxonomic levels, but limited analyses have been performed among closely related genera with contrasting floral traits due to the lack of fully resolved phylogenetic relationships. Here, we used four representative transcriptomes to develop an exome capture (target enrichment) bait for the entire subfamily and applied it to the Anthonotha clade using a complete data set (61 specimens) representing all extant floral diversity. Our phylogenetic analyses recovered congruent topologies using ML and Bayesian methods. Anthonotha was recovered as monophyletic contrary to the remaining three genera (Englerodendron, Isomacrolobium and Pseudomacrolobium), which form a monophyletic group sister to Anthonotha. We inferred a total of 35 transitions for the seven floral traits (pertaining to flower symmetry, petals, stamens and staminodes) that we analyzed, suggesting that at least 30% of the species in this group display transitions from the ancestral condition reconstructed for the Anthonotha clade. The main transitions were towards a reduction in the number of organs (petals, stamens and staminodes). Despite the high number of transitions, our analyses indicate that the seven characters are evolving independently in these lineages. Petal morphology is the most labile floral trait with a total of seven independent transitions in number and seven independent transitions to modification in petal types. The diverse petal morphology along the dorsoventral axis of symmetry within the flower is not associated with differences at the micromorphology of petal surface, suggesting that in this group all petals within the flower might possess the same petal identity at the molecular level. Our results provide a solid evolutionary framework for further detailed analyses of the molecular basis of petal identity. © 2019 Elsevier Inc., SCOPUS: ar.j, info:eu-repo/semantics/published

Phylogenomics is increasingly used to infer deep-branching relationships while revealing the complexity of evolutionary processes such as incomplete lineage sorting, hybridization/introgression and polyploidization. We investigate the deep-branching relationships among subfamilies of the Leguminosae (or Fabaceae), the third largest angiosperm family. Despite their ecological and economic importance, a robust phylogenetic framework for legumes based on genome-scale sequence data is lacking. We generated alignments of 72 chloroplast genes and 7,621 homologous nuclear encoded proteins, for 157 and 76 taxa, respectively. We analysed these with Maximum Likelihood, Bayesian Inference, and a multi-species coalescent summary method, and evaluated support for alternative topologies across gene trees. We resolve the deepest divergences in the legume phylogeny despite lack of phylogenetic signal across all chloroplast genes and the majority of nuclear genes. Strongly supported conflict in the remainder of nuclear genes is suggestive of incomplete lineage sorting. All six subfamilies originated nearly simultaneously, suggesting that the prevailing view of some subfamilies as "basal" or "early-diverging" with respect to others should be abandoned, which has important implications for understanding the evolution of legume diversity and traits. Our study highlights the limits to phylogenetic resolution in relation to rapid successive speciation.

Canadensys is an associate GBIF node in Canada, officially established as a node in 2014, but publishing data on GBIF since 2011. Since then, Canadensys has grown from nine institutions to a network of nearly 25 institutions that publish biodiversity data and we have migrated from an in-house explorer, to a Living Atlases (LA) framework. Canadensys publishes data curated or collected by Canadian universities, museums, as well as municipalities and non govermental organizations (NGOs). Establishing a new network can be challenging, but several resources and programs exist to help node managers and node participants initiate the publication process. Keeping an established network alive while continuing to grow and to develop new methods and technologies is also an important challenge, especially in a context where institutions are geographically separated across large distances, and where funds are scarce or mostly oriented towards highly innovative projects. With the aim to reach both established and new participants across Canada and from adjacent regions in the USA, and in order to help them to familiarize themselves with the new framework based on LA, we organized three workshops on data publication and data usage. Partially funded through a GBIF CESP project, this series of workshops was developed in partnership with international, regional and national partners such as iDigBio, OBIS Canada and GBIF Spain. The workshops helped new participants prepare and publish data, and allowed established publishers to enrich and update their resources on Canadensys and GBIF. The project also highlighted some of the challenges our network is facing, such as funding, infrastructure, human resources, and communication. Feedback from participants shows that the workshops were successfull in terms of capacity enhancement, giving knowledge and tools to data manager in order to prepare and publish standardize data, as well as to transfer that knowledge in their respective institutions. All materials and documentation developed during this project will be made available on Canadensys, allowing everyone interested to follow the curriculum. Sharing our experience will be useful for other nodes wanting to introduce the LA framework to their users and to enhance capacities in the network.

The consequences of the Cretaceous-Paleogene (K-Pg) boundary (KPB) mass extinction for the evolution of plant diversity are poorly understood, even although evolutionary turnover of plant lineages at the KPB is central to understanding the assembly of the Cenozoic biota. One aspect that has received considerable attention is the apparent concentration of whole genome duplication (WGD) events around the KPB, which may have played a role in survival and subsequent diversification of plant lineages. In order to gain new insights into the origins of Cenozoic biodiversity, we examine the origin and early evolution of the legume family, one of the most important angiosperm clades that rose to prominence after the KPB and for which multiple WGD events are found to have occurred early in its evolution. The legume family (Leguminosae or Fabaceae), with c. 20.000 species, is the third largest family of Angiospermae, and is globally widespread and second only to the grasses (Poaceae) in economic importance. Accordingly, it has been intensively studied in botanical, systematic and agronomic research, but a robust phylogenetic framework and timescale for legume evolution based on large-scale genomic sequence data is lacking, and key questions about the origin and early evolution of the family remain unresolved. We extend previous phylogenetic knowledge to gain insights into the early evolution of the family, analysing an alignment of 72 protein-coding chloroplast genes and a large set of nuclear genomic sequence data, sampling thousands of genes. We use a concatenation approach with heterogeneous models of sequence evolution to minimize inference artefacts, and evaluate support and conflict among individual nuclear gene trees with internode certainty calculations, a multi-species coalescent method, and phylogenetic supernetwork reconstruction. Using a set of 20 fossil calibrations we estimate a revised timeline of legume evolution based on a selection of genes that are both informative and evolving in an approximately clock-like fashion. We find that the root of the family is particularly difficult to resolve, with strong conflict among gene trees suggesting incomplete lineage sorting and/or reticulation. Mapping of duplications in gene family trees suggest that a WGD event occurred along the stem of the family and is shared by all legumes, with additional nested WGDs subtending subfamilies Papilionoideae and Detarioideae. We propose that the difficulty of resolving the root of the family is caused by a combination of ancient polyploidy and an alternation of long and very short internodes, shaped respectively by extinction and rapid divergence. Our results show that the crown age of the legumes dates back to the Maastrichtian or Paleocene and suggests that it is most likely close to the KPB. We conclude that the origin and early evolution of the legumes followed a complex history, in which multiple nested polyploidy events coupled with rapid diversification are associated with the mass extinction event at the KPB, ultimately underpinning the evolutionary success of the Leguminosae in the Cenozoic.

Detarioideae is well known for its high diversity of floral traits, including flower symmetry, number of organs, and petal size and morphology. This diversity has been characterized and studied at higher taxonomic levels, but limited analyses have been performed among closely related genera with contrasting floral traits due to the lack of fully resolved phylogenetic relationships. Here, we used four representative transcriptomes to develop an exome capture bait for the entire subfamily and applied it to the Anthonotha clade using a complete data set (61 specimens) representing all extant floral diversity. Our phylogenetic analyses recovered congruent topologies using ML and Bayesian methods. The genus Anthonotha was recovered as monophyletic contrary to the remaining three genera (Englerodendron, Isomacrolobium and Pseudomacrolobium), which form a monophyletic group sister to Anthonotha. We inferred a total of 35 transitions for the seven floral traits (pertaining to flower symmetry, petals, stamens and staminodes) that we analyzed, suggesting that at least 30% of the species in this group display transitions from the ancestral condition reconstructed for the Anthonotha clade. The main transitions were towards a reduction in the number of organs (petals, stamens and staminodes). Despite the high number of transitions, our analyses indicate that the seven characters are evolving independently in these lineages. Petal morphology is the most labile floral trait with a total of seven independent transitions in number and seven independent transitions to modification in petal types. The diverse petal morphology along the dorsoventral axis of symmetry within the flower is not associated with differences at the micromorphology of petal surface, suggesting that in this group all petals within the flower might possess the same petal identity at the molecular level. Our results provide a solid evolutionary framework for further detailed analyses of the molecular basis of petal identity.

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.

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.

Orphanodendron is a taxonomically and geographically isolated South American genus of two species. When first described by Barneby and Grimes in 1990, the genus was placed in Leguminosae subfamily Caesalpinioideae, but that placement was doubted and the name Orphanodendron (Gr. orphanos, orphan + dendron, tree) was chosen to reflect the uncertain subfamilial relationship of the genus. In this study, nucleotide sequence data from five Orphanodendron specimens were added to 662 other, previously sampled, Leguminosae taxa representing all three currently recognized subfamilies (Caesalpinioideae, Mimosoideae and Papilionoideae) in a matK maximum parsimony analysis that resolved Orphanodendron as a member of the genistoid s.l. clade of subfamily Papilionoideae. Two additional Bayesian phylogenetic analyses with reduced taxon sampling of plastid (matK combined with trnL-F) and nuclear (ITS) loci strongly support the monophyly of Orphanodendron and unambiguously establish Orphanodendron as a member of the genistoid sensu lato clade. Although our plastid phylogenetic analysis finds relatively low support for a sister-group relationship with the African genus Camoensia, the nuclear-encoded ITS resolves Orphanodendron as sister to the Bowdichia clade with strong support and Camoensia as sister to other core genistoids. The phylogenetic resolution of Orphanodendron as a member of the genistoid s.l. legumes based on nuclear and plastid sequences will undoubtedly advance future evolutionary investigations of this Colombian endemic tropical tree genus.

The legume subfamily Detarioideae is exceptionally diverse in tropical Africa and Madagascar, compared to South America or Asia, a trend contrary to that shown by most other pantropical plant groups. We aim to elucidate the process of diversification giving rise to these high diversity levels by focussing our investigations on the Daniellia clade, which is present in both Africa and Madagascar. The Daniellia clade is an early-diverging lineage of subfamily Detarioideae (Leguminosae; pea family) and consists of three genera: Daniellia, Brandzeia and Neoapaloxylon. The species belonging to this group exhibit a wide range of habitat types. The Madagascar endemics Brandzeia (1 species) and Neoapaloxylon (3 species) occupy dry woodlands and arid succulent habitats respectively. Daniellia alsteeniana and D. oliveri are found in savannahs while the remaining eight species within Daniellia all occupy rainforest habitats. Phylogenetic analyses were generated from a dense, multi-individual species level sampling of the clade. Divergence time estimates were carried out using a molecular clock method to investigate biogeographical patterns and shifts in habitat types within the Daniellia clade, and conservation assessments were conducted to determine the levels of extinction risks these species are facing. We estimate that the Daniellia clade first emerged during the Early Eocene from an ancestor present in the rainforests of North Africa at that time, reflecting an ancestral habitat preference. There was a first major split over the course of the Eocene, giving rise to both African rainforest and Madagascan savannah lineages. With the emergence of a drier climate and vegetation type in Africa during the Eocene, it is likely that a dry-climate adapted lineage from the Daniellia clade ancestor could have dispersed through suitable savannah or woodland regions to reach Madagascar, subsequently giving rise to the savannah-adapted ancestor of Brandzeia and Neoapaloxylon in the Early Miocene. The African rainforest lineage gave rise to the genus Daniellia, which is postulated to have first diversified in the Middle Miocene, while savannah species of Daniellia emerged independently during the Pliocene, coinciding with the global rise of C4-dominated grasslands. More than half of the species in the Daniellia clade are near threatened or threatened, which highlights the need to understand the threats of anthropogenic pressures and climate change these species are facing to prioritise their conservation.

The flora of the Neotropics is unmatched in its diversity, however the mechanisms by which diversity has accumulated are debated and largely unclear. The Brownea clade (Leguminosae) is a characteristic component of the Neotropical flora, and the species within it are diverse in their floral morphology, attracting a wide variety of pollinators. This investigation aimed to estimate species divergence times and infer relationships within the group, in order to test whether the Brownea clade followed the 'cradle' or 'museum' model of diversification, i.e. whether species evolved rapidly over a short time period, or gradually over many millions of years. We also aimed to trace the spatio-temporal evolution of the clade by estimating ancestral biogeographical patterns in the group. We used BEAST to build a dated phylogeny of 73 Brownea clade species using three molecular markers (ITS, trnK and psbA-trnH), resulting in well-resolved phylogenetic relationships within the clade, as well as robust divergence time estimates from which we inferred diversification rates and ancestral biogeography. Our analyses revealed an Eocene origin for the group, after which the majority of diversification happened in Amazonia during the Miocene, most likely concurrent with climatic and geological changes caused by the rise of the Andes. We found no shifts in diversification rate over time, suggesting a gradual accumulation of lineages with low extinction rates. These results may help to understand why Amazonia is host to the highest diversity of tree species on Earth.

The generic affiliation of the Andean species Caesalpinia trichocarpa, C. mimosifolia, and their close relatives has remained uncertain in all recent studies of Caesalpinia s.l. (Leguminosae, subfamily Caesalpinioideae). A new densely sampled phylogeny based on four DNA sequence regions (rps16, trn D-trnT, ycf6- psbM, ITS) strongly supports the monophyly of an Andean clade. We propose that despite the lack of obvious diagnostic morphological synapomorphies, this Andean group should be considered as a distinct genus, here described as the new genus Arquita. Phylogenetic analyses also suggest a problem with species delimitation in this group. Within C. trichocarpa, accessions from disjunct geographic areas in Argentina, Bolivia and Peru each form a robustly supported, unresolved clade that includes C. mimosifolia. The morphological and genetic cohesiveness of the C. trichocarpa complex is investigated using morphometric phenetic analyses of qualitative and quantitative flower and leaf traits, and reconstruction of a densely sampled phylogeny using three plastid and one nuclear ribosomal DNA sequence loci. Our results suggest that the most geographically isolated of these clades, narrowly endemic to two inter-Andean valleys in central-north Peru and separated by ∼1350 km, and extensive high Andean cordilleras above 4000 m, from the nearest populations in Bolivia, represents a genetically highly distinct and morphologically cryptic lineage here described as a new species (Arquita grandiflora). A full taxonomic account of the new genus Arquita and its component species is provided, with a distribution map and a key to the species.

Since its description, almost 100 years ago, the genus Dinizia has been treated as monospecific, comprising the single canopy-emergent species Dinizia excelsa Ducke which grows in non-flooded Amazonian forests of Guyana, Suriname and seven states of northern and central-western Brazil. Dinizia jueirana-facao G. P. Lewis & G. S. Siqueira, which grows in a restricted area of semi-deciduous Atlantic rain forest in Espirito Santo state, Brazil, is described as a new species in the genus. The new species is also a canopy-emergent of impressive stature. We provide descriptions for both species, a key to species identification, a distribution map and the new species is illustrated. Fossil leaves, inflorescences and fruit provide evidence for a Dinizia-like ancestor occurring in south-eastern North America during the Eocene. In contrast to D. excelsa where pollen is dispersed in tetrads, the pollen of D. jueirana-facao is shed in monads. D. jueirana-facao is considered critically endangered following IUCN conservation criteria, whereas D. excelsa is assessed to be of least concern. A lectotype is designated for D. excelsa.

Atlas of Living Australia (ALA) [*1] framework is an open source infrastructure used to share biodiversity data through severals modules. Adding datasets in ALA is an important step that give access to occurrences. Setting of parameters needs to be accurate in order to correctly view occurrences. Biocache-hub [*2] is an interface that allows research on ingested occurrences by Biocache-store [*3]. It's an advanced data explorer with filters. This training will be divided in two parts. First part will provide tools and techniques to add datasets, from a csv local resource to a GBIF dataset DWC file, within the administration management of the Collectory module [*4]. It will also present the important steps to link occurrences with datasets and how to update a dataset. Second part, within user view, will present the access to occurrences and options available from a Simple search to a Spatial search.

With over 780 million records, the Global Biodiversity Information Facility (GBIF) is an international consortium whose goal is to collect data on biodiversity and make them available, free and online, to everyone. Canadensys (http://www.canadensys.net/) is a network of researchers, collectors, curators, information technologists, students, and educators that shares data on the occurrence and taxonomic identity of plants, animals and fungi in Canada. It is an associate participant of GBIF. The French node of GBIF, GBIF France (http://www.gbif.fr/), among other objectives, provides and helps French data publishers to connect their data through the GBIF network. Since 2014, GBIF France's technical team has installed and configured their data portal using Atlas of Living Australia (ALA) tools. One of the main missions of GBIF is to assist nodes in creating global and regional collaborations in order to transfer knowledge on tools and methods which help providers enhance their data and upload them into the GBIF network. To achieve this, GBIF initiated the Capacity Enhancement Support Program (CESP) (http://www.gbif.org/programme/capacity-support). The mentoring activity presented in this poster is one of the five types of activities supported by CESP. The amount of data served through Canadensys has increased dramatically during the past years. The consequence is that its current system is not sufficiently powerful to effectively treat this increased volume of data. In order to meet this requirement, Canadensys has begun to configure and install its system based on the ALA framework. Through this CESP mentoring activity, GBIF France is helping Canadensys launch its own data portal by providing assistance on technical specifications, such as server configuration and customization. In addition to this main objective, GBIF France and Canadensys aim to extend the ALA community and include French-speaking countries (especially in Africa and the Caribbean). In fact, projects with the aforementioned countries have already been proposed through CESP and other calls. Efforts to improve the ALA integration documentation and provide French translations are underway. In this poster, Canadensys presents its new system and its functionalities. We also describe the collaboration between GBIF France and Canadensys and the improvements made on the documentation, which will facilitate installation of national or regional data portals in French-speaking countries.

A new species of Orphanodendron (Leguminosae, Papilionoideae), Orphanodendron grandiflorum, is described and illustrated. The new species was discovered in the municipality of Bolivar, department of Santander, in the Eastern Cordillera of Colombia, and constitutes the second described species of the genus Orphanodendron.

Premise of research. Gilbertiodendron is a genus endemic to Africa with ∼30 species made up of trees of primary dry-land, riverine, and gallery forests. Recently, the west and central African monotypic genus Pellegriniodendron was merged into Gilbertiodendron. Gilbertiodendron is one of 17 genera that form the exclusively African Berlinia clade, and this study presents the findings of a phylogenetic analysis designed to evaluate the generic limits of Gilbertiodendron and its relationships within the Berlinia clade.Methodology. To test the monophyly of Gilbertiodendron and its relationships with other genera, we analyzed nucleotide sequence data from the nuclear ribosomal internal transcribed spacer and the plastid trnL intron and trnL-F intergenic spacer, using parsimony and Bayesian analyses.Pivotal results. Gilbertiodendron is recovered as monophyletic, including all the samples previously recognized as Pellegriniodendron diphyllum.Conclusions. The placement of Pellegriniodendron in synonymy with Gilber...

Premise of research. We examine floral evolution and phylogenetic relationships in the monophyletic Detarieae and related lineages of Caesalpinioideae. Tribe Detarieae (82 genera) includes nearly half of the genera in subfamily Caesalpinioideae and represents some of the most diverse legumes with respect to floral morphology.Methodology. A total of 67 floral ontogenetic and morphological characters were combined with DNA sequences from the plastid trnL-F and matK regions of 34 Detarieae species and representatives of Cassieae, Cercideae, Caesalpinieae, Papilionoideae, and Mimosoideae, for which we have near-complete ontogenetic series. The morphological and ontogenetic characters were optimized onto the resulting most parsimonious phylogenetic trees and Bayesian topology to study character evolution.Pivotal results. Our study supports previously proposed relationships within the tribe Detarieae and among caesalpinioid lineages and indicates that certain features (bracteole and hypanthium characters, sepal...

Caesalpinia sensu lato, in its broadest circumscription, is a pantropical group of c.150 species of trees, shrubs and lianas many of which grow in arid habitats of the Succulent Biome (sensu Schrire et al., 2005), and especially in the seasonally dry tropical forests of Central and South America and the Caribbean. As traditionally circumscribed, Caesalpinia s.l. was one of the largest genera in tribe Caesalpinieae, but seven generic segregates, namely Coulteria, Erythrostemon, Guilandina, Libidibia, Mezoneuron, Poincianella and Tara were reinstated by Lewis (2005), greatly reducing the number of species remaining in Caesalpinia sensu stricto. Nevertheless, doubts remain regarding the monophyly and delimitation of some of these segregate genera, which have not been thoroughly tested using molecular data, and this has hindered the establishment of a comprehensive generic classification of the broader Caesalpinia Group as a whole. Here we present a new phylogeny of the Caesalpinia Group, based on plastid rps16 sequences and dense taxon sampling including 18 of the 21 genera of the Caesalpinia Group and 98 of the c.150 species of Caesalpinia s.l. Our results support the monophyly of five of the genera reinstated by Lewis, but the three other genera (including Caesalpinia s.s.) are non-monophyletic and need to be re-evaluated. Furthermore, three robustly supported newly discovered clades within Caesalpinia s.l. potentially merit recognition as distinct genera pending complete investigation of diagnostic morphological characters. Uncertainties concerning the delimitation of some clades are discussed especially in relation to the extensive morphological variation found within Caesalpinia s.l.

Numerous studies have identified low copy nuclear genes (LCNG) with phylogenetic potential throughout angiosperms, several specifically focused on Leguminosae. However, phylogenetic resolution at the species- to subspecies-level is often inferred based only on a small subset of taxa scattered throughout the higher level study group. This study aims to reassess the phylogenetic resolution of 19 previously published nuclear regions in Leguminosae using 18 species from two clades of the Caesalpinieae representing both distantly related genera and closely related species. Nuclear regions were amplified and aligned throughout the sampled taxa. Sequences were cloned when polymorphism was noted. The plastid loci matK, rps16, trnL, trnD–trnT and the nuclear ribosomal ITS regions were also analyzed for comparison. Phylogenetic analyses using parsimony were performed on individual matrices. Three nuclear regions were eliminated due to the non-specificity of the primers (RNAH, PTSB, GI). Four regions showed lower resolution than predicted from previous studies (MMK1, CYB6, RBPCO, EFGC), while three revealed greater resolution than anticipated (SQD1, AT103, EIF3E). Three other markers indicated previously unidentified duplication events for the genus Caesalpinia s.l. (ATCP and AROB) and at the base of the Caesalpinia and Peltophorum clades (CALTL). Phylogenies reconstructed from the intron-spanning regions AIGP, SHMT, AT103 and EIF3E are congruent with ITS and plastid data and show the best phylogenetic potential for studies of closely related species of caesalpinioid legumes. We present a screening strategy for the evaluation of LCNG for phylogenetic studies.

Legume subfamily Caesalpinioideae accommodates approximately 2250 species in 171 genera which traditionally are placed in four tribes: Caesalpinieae, Cassieae, Cercideae and Detarieae. The monophyletic tribe Detarieae includes the Amherstieae subclade which contains about 55 genera. Our knowledge of the relationships among those genera is good in some cases but for many other genera phylogenetic relationships have been unclear. The non-monophyletic nature of at least two amherstioid genera, Cynometra and Hymenostegia has also complicated the picture. During the course of a multi-disciplinary study of Hymenostegia sensu lato, which includes phylogenetic analyses based on matK and trnL data, we have recovered the “Scorodophloeus clade”, an exclusively tropical African clade of four genera which includes the eponymous genus Scorodophloeus, two undescribed generic segregates of Hymenostegia sensu lato, and the previously unsampled rare monospecific genus Micklethwaitia from Mozambique. Zenkerella is suggested as a possible sister genus to the Scorodophloeus clade. A distribution map is presented of the seven species that belong to the Scorodophloeus clade.

Wild roses are widespread throughout North America but it is only recently that commercial interests have increased worldwide for rosehip products. Rosehip production under field conditions is new for North American wild roses and the cultivated materials are not well characterized. Despite recent phylogenetic studies on North American roses, micro-evolutionary studies at regional level in terms of genetic and metabolite diversity are scarce. We have characterized 30 wild rose ecotypes collected from different regions Prince Edward Island using microsatellite (SSR) markers, SNP of the chloroplast trnaL intron and the nuclear gene GAPDH, ploidy determination as well as the metabolite profiling for major phenolics and fatty acids. A total of 244 SSR alleles, with an average of 12.2 per marker were observed. The polymorphic information content (PIC) ranged between 0.00 and 0.97, with an average of 0.70. Cluster analysis showed three main clusters, cluster 3 showing the greatest diversity. Within each cluster, the ecotypes also showed large metabolite diversity, reflective of their genetic diversity. The data suggests the potential for the cultivation of a given ecotype for its unique metabolite profile or it incorporation in breeding programs. The ploidy and phylogenetic studies showed that all 30 ecotypes were tetraploid and that the collection is consisted of Rosa virginiana and its natural hybrids with Rosa carolina.

Apuleia leiocarpa (Vogel) J. F. Macbr. is a South American tree species belonging to the caesalpinioid subfamily of the Leguminosae. Phylogenetic analyses have placed Apuleia into the Dialiinae s.l. clade, with which it shares numerous morphological similarities, including dichasial cymose inflorescences. The genus has also been reported to be andromonoecious, a trait not seen elsewhere in its clade and only infrequently in the Caesalpinioideae. Scanning electron microscopy and stereomicroscopy were used to investigate the floral morphology of A. leiocarpa. It was found that while hermaphrodite flowers produced a single carpel and two stamens, staminate flowers developed three stamens but showed no signs of any carpel development. The third stamen fills the volume of the missing carpel within the bud as it grows. Inflorescences also appear to produce approximately four times as many staminate as hermaphrodite flowers. Both this high male-to-bisexual ratio and the early determination of gender seen in Apul...

PREMISE OF THE STUDY The Dialioideae is an early diverging clade of caesalpinioid legumes containing approximately 85 species in 17 genera. Dialioideae floral morphology is highly variable and may provide clues to caesalpinioid evolution, but a well-resolved phylogeny is needed. Here, we have carried out a comprehensive morphological study of 78 Dialioideae and four outgroup species. METHODS For all available Dialioideae DNA samples, the plastid rpS16 and trnL introns were sequenced. A combined phylogenetic analysis using the parsimony criterion was completed on a reduced taxon set for which both molecular and morphological data were available. Highly supported clades from the strict consensus tree of this analysis were then used to constrain the nodes of a second analysis on an expanded taxon set with missing molecular data for some taxa. KEY RESULTS Several new, highly supported relationships have been discovered at the species and genus levels. The loss of the antepetalous stamen whorl was found to be a synapomorphy for most of the clade. CONCLUSIONS A high degree of organ loss is common in the Dialioideae and often results in a bilaterally symmetrical flower. The absence of consistent morphological features in the Dialioideae, coupled with the small size of each florally diagnosed genus, suggests a lack of canalization in the floral evolution in early diverging legume lineages.

The Caesalpinia group is a large pantropical clade of ca. 205 species in subfamily Caesalpinioideae (Leguminosae) in which generic delimitation has been in a state of considerable flux. Here we present new phylogenetic analyses based on five plastid and one nuclear ribosomal marker, with dense taxon sampling including 172 (84%) of the species and representatives of all previously described genera in the Caesalpinia group. These analyses show that the current classification of the Caesalpinia group into 21 genera needs to be revised. Several genera (Poincianella, Erythrostemon, Cenostigma and Caesalpinia sensu Lewis, 2005) are non-monophyletic and several previously unclassified Asian species segregate into clades that merit recognition at generic rank. In addition, the near-completeness of our taxon sampling identifies three species that do not belong in any of the main clades and these are recognised as new monospecific genera. A new generic classification of the Caesalpinia group is presented including a key for the identification of genera, full generic descriptions, illustrations (drawings and photo plates of all genera), and (for most genera) the nomenclatural transfer of species to their correct genus. We recognise 26 genera, with reinstatement of two previously described genera (Biancaea Tod., Denisophytum R. Vig.), re-delimitation and expansion of several others (Moullava, Cenostigma, Libidibia and Erythrostemon), contraction of Caesalpinia s.s. and description of four new ones (Gelrebia, Paubrasilia, Hererolandia and Hultholia), and make 75 new nomenclatural combinations in this new generic system.

The Caesalpinieae grade (Leguminosae) forms a morphologically and ecologically diverse group of mostly tropical tree species with a complex evolutionary history. This grade comprises several distinct lineages, but the exact delimitation of the group relative to subfamily Mimosoideae and other members of subfamily Caesalpinioideae, as well as phylogenetic relationships among the lineages are uncertain. With the aim of better resolving phylogenetic relationships within the Caesalpinieae grade, we investigated the utility of several nuclear markers developed from genomic studies in the Papilionoideae. We cloned and sequenced the low copy nuclear gene sucrose synthase (SUSY) and combined the data with plastid trnL and matK sequences. SUSY has two paralogs in the Caesalpinieae grade and in the Mimosoideae, but occurs as a single copy in all other legumes tested. Bayesian and maximum likelihood phylogenetic analyses suggest the two nuclear markers are congruent with plastid DNA data. The Caesalpinieae grade is divided into four well-supported clades (Cassia, Caesalpinia, Tachigali and Peltophorum clades), a poorly supported clade of Dimorphandra Group genera, and two paraphyletic groups, one with other Dimorphandra Group genera and the other comprising genera previously recognized as the Umtiza clade. A selection analysis of the paralogs, using selection models from PAML, suggests that SUSY genes are subjected to a purifying selection. One of the SUSY paralogs, under slightly stronger positive selection, may be undergoing subfunctionalization. The low copy SUSY gene is useful for phylogeny reconstruction in the Caesalpinieae despite the presence of duplicate copies. This study confirms that the Caesalpinieae grade is an artificial group, and highlights the need for further analyses of lineages at the base of the Mimosoideae.

The legume subfamily Caesalpinioideae is a paraphyletic grade, within which are nested the monophyletic subfamilies Mimosoideae and Papilionoideae. Although higher level relationships within Caesalpinioideae are now better understood, few studies have examined generic and species level relationships. A morphological and molecular phylogenetic analysis of selected members of the Brownea clade (Detarieae: Caesalpinioideae) is presented here, focusing on relationships within and among the genera Elizabetha, Heterostemon, Paloveopsis, and Paloue. Morphological characters (125) and DNA sequence data from the plastid trnL intron and nuclear ITS were used to reconstruct phlogenetic relationships. These results indicate that (1) Heterostemon is monophyletic; (2) the majority of Elizabetha species form a poorly supported, monophyletic group sister to Paloue; and (3) Paloveopsis is nested within Paloue. Intergeneric hybridization between species of Paloue and Elizabetha has been identified and traditional generic, species, and intraspecies boundaries are assessed and reevaluated using the results of the combined phylogenetic analysis.