Leguminosae are one of the most diverse flowering-plant groups today, but the evolutionary history of the family remains obscure because of the scarce early fossil record, particularly from lowland tropics. Here, we report ∼500 compression or impression specimens with distinctive legume features collected from the Cerrejón and Bogotá Formations, Middle to Late Paleocene of Colombia. The specimens were segregated into eight fruit and six leaf morphotypes. Two bipinnate leaf morphotypes are confidently placed in the Caesalpinioideae and are the earliest record of this subfamily. Two of the fruit morphotypes are placed in the Detarioideae and Dialioideae. All other fruit and leaf morphotypes show similarities with more than one subfamily or their affinities remain uncertain. The abundant fossil fruits and leaves described here show that Leguminosae was the most important component of the earliest rainforests in northern South America c. 60–58 million years ago.

Extrafloral nectaries (EFNs) mediating ecologically important ant–plant protection mutualisms are especially common and unusually diverse in the Leguminosae. We present the first comprehensively curated list of legume genera with EFNs, detailing and illustrating their systematic and phylogenetic distributions, locations on the plant, morphology and anatomy, on the basis of a unified classification of EFN categories and a time-calibrated phylogeny, incorporating 710 of the 768 genera. This new synthesis, the first since Mckey (1989)’s seminal paper, increases the number of genera with EFNs to 153 (20% of legumes), distributed across subfamilies Cercidoideae (1), Detarioideae (19), Caesalpinioideae (87) and Papilionoideae (46). EFNs occur at nine locations, and are most prevalent on vegetative plant parts, especially leaves (74%) and inflorescence axes (26%). Four main categories (with eight subcategories) are recognised and include the following: formless, trichomatic (exposed, hollow), parenchymatic (embedded, pit, flat, elevated) and abscission zone EFNs (non-differentiated, swollen scars). Phylogenetic reconstruction of EFNs suggests independent evolutionary trajectories of different EFN types, with elevated EFNs restricted almost exclusively to Caesalpinioideae (where they underwent spectacular morphological disparification), flat EFNs in Detarioideae, swollen scar EFNs in Papilionoideae, and Cercidoideae is the only subfamily bearing intrastipular EFNs. We discuss the complex evolutionary history of EFNs and highlight future research directions.

Next-generation sequencing (NGS) technologies and applications have enabled numerous critical advances in legume biology, from marker discovery to whole-genome sequencing, and will provide many new avenues for legume research in the future. The past 6 years in particular have seen revolutionary advances in legume science because of the use of high-throughput sequencing, including the development of numerous types of markers and data useful for evolutionary studies above and below the species level that have enabled resolution of relationships that were previously unattainable. Such resolution, in turn, affords opportunities for hypothesis testing and inference to improve our understanding of legume biodiversity and the patterns and processes that have created one of the most diverse plant families on earth. In addition, the genomics era has seen significant advances in our understanding of the ecology of legumes, including their role as nitrogen fixers in global ecosystems. The accumulation of genetic and genomic data in the form of sequenced genomes and gene-expression profiles made possible through NGS platforms has also vastly affected plant-breeding and conservation efforts. Here, we summarise the knowledge gains enabled by NGS methods in legume biology from the perspectives of evolution, ecology, and development of genetic and genomic resources.

Plant mitochondrial genomes are often difficult to assemble because of frequent recombination mediated by repeats. Only a few mitochondrial genomes have been characterised in subfamily Papilionoideae of Leguminosae. Here, we report the complete mitochondrial genome of Castanospermum australe A.Cunn. & C.Fraser, an important medicinal and ornamental species in the Aldinoid clade of Papilionoideae. By mapping paired-end reads, seven hypothetical subgenomic conformations were rejected and two hypothetical complete isometric mitochondrial genome conformations that differed by a 64-kb inversion were strongly supported. Quantitative assessment of repeat-spanning read pairs showed a major conformation (MC1) and a minor conformation (MC2). The complete mitochondrial genome of C. australe was, thus, generated as 542 079 bp in length, with a high depth of coverage (∼389.7×). Annotation of this mitochondrial genome yielded 58 genes encoding 37 proteins, 18 tRNAs and three rRNAs, as well as 17 introns and three medium-sized repeats (133, 119 and 114 bp). Comparison of 10 mitochondrial genomes from Papilionoideae demonstrated significant variation in genome size, structure, gene content and RNA editing sites. In addition, mitochondrial genes were shown to be potentially useful in resolving the deep relationships of Papilionoideae.

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.

Southern Africa has a rich legume flora comprising 133 indigenous genera and 1620 indigenous species, of which 1059 species (65%) are endemic to the flora of southern Africa region. An additional 128 non-indigenous species have become naturalised, of which 59 are invasive, resulting in 1748 species from 165 genera. There are 22 (17%) endemic genera, one endemic tribe (Hypocalyptieae) and one near-endemic tribe (Podalyrieae, with 122 of the 123 species endemic). The diversity of uses (given as total/indigenous spp.) include food and beverages (127/115 spp.), medicine (338/291 spp.), magic and charms (113/104 spp.), timber (59/55 spp.), firewood (43/31 spp.) and 10 more minor use categories. Regression analyses showed that the levels of endemism in subfamilies and tribes are directly related to the numbers of species but that the number of useful species is not related to species numbers, except for the non-papilionoid subfamilies (all uses) and non-genistoid papilionoids (medicinal uses only). The Phaseoleae and Millettieae showed high residual values in several analyses, indicating that they have been favoured in the selection of useful plants. Diversity in habit and chemistry seems to explain at least partly the use patterns.

Two new legume species, Poecilanthe goiasana G.P.Lewis from Brazil and Poecilanthe boliviana G.P.Lewis from Bolivia, are described and illustrated. Previously seven species of the genus were recorded from Brazil, and one from Bolivia. A summary is given of the current circumscription of the papilionoid legume tribe Brongniartieae Hutch., to which Poecilanthe belongs.

Taxonomic studies of Tephrosia Pers. (Leguminosae, Papilionoideae, Millettieae) in South America have highlighted the need to resolve some nomenclatural issues. Five new synonyms are proposed and a new species is described. Nine lectotypes of accepted names and synonyms, and one neotype, are here designated. An identification key to the taxa occurring in South America is also presented.

On the basis of a new phylogeny of the Detarioideae, with a particular focus on Englerodendron Harms, Anthonotha P.Beauv. and related genera, the possible options for delimiting monophyletic genera are discussed. As a result, Isomacrolobium Aubrév. & Pellegr. and Pseudomacrolobium Hauman are synonymised under Englerodendron. The following 12 new combinations are formed within the expanded Englerodendron: E. brachyrhachis (Breteler) Estrella & Ojeda, E. explicans (Baill.) Estrella & Ojeda, E. graciliflorum (Harms) Estrella & Ojeda, E. hallei (Aubrév.) Estrella & Ojeda, E. isopetalum (Harms) Breteler & Wieringa, E. lebrunii (J.Léonard) Estrella & Ojeda, E. leptorrhachis (Harms) Estrella & Ojeda, E. mengei (De Wild.) Estrella & Ojeda, E. nigericum (Baker f.) Estrella & Ojeda, E. obanense (Baker f.) Estrella & Ojeda, E. triplisomere (Pellegr.) Estrella & Ojeda and E. vignei (Hoyle) Estrella & Ojeda. A key to identification of the 17 species now recognised within Englerodendron is presented.