The generic relationships within the core Millettieae have not been well resolved to date. Millettia is considered one of the most problematic genera to classify within the core Millettieae, with approximately 150 species found in Asia and Africa. Recent molecular evidence has indicated that Millettia is highly polyphyletic. In this study, we utilized plastomes and single-copy nuclear genes from genome skimming sequencing to reconstruct the generic relationships and estimate the divergence time for the core Millettieae, focusing on the Asian species of Millettia. Our results revealed a broader circumscription of the core Millettieae with the inclusion of the Phaseoleae subtribe Ophrestiinae, consisting of 7 clades and 14 subclades within two main groups (canavanine and non-canavanine). The Asian species of Millettia were grouped into three distinct, well-supported subclades, leading us to propose a much narrower generic concept of Millettia, along with the reinstatements of the genera Pongamia and Otosema. Millettia s.str. was restricted to include only seven species. Pongamia was recognized as a medium-sized genus that includes Fordia and Ibatiria, with approximately 56 species. Otosema, usually treated as a subgenus or section of Millettia, was resurrected as a distinct genus with three species. Our findings also indicated that the sampled African Millettia species belong to three subclades distinct from the Asian Millettia subclades, warranting further investigation in future studies. The dating result showed that the early rapid diversification of the core Millettieae during the Mid-Miocene Climatic Optimum involved several major problematic genera, including Derris s.lato, Lonchocarpus s.lato, and Millettia s.lato, which may explain why these plant groups are difficult to classify. These results offer new insights into the phylogeny and taxonomy of the core Millettieae.

Garcinia L. is a pantropically distributed genus comprised of at least 250 species of shrubs and trees and has centers of diversity located in Africa/Madagascar, Australasia, and Southeast Asia. The genus is notable due to its extreme diversity of floral form, common presence in lowland tropical rainforests worldwide, and potential pharmacological value. Across its entire geographic range, Garcinia lacks a recent taxonomic revision, with the last genus-level taxonomic treatment of Garcinia conducted over 40 years ago. In order to provide an evolutionary-based framework for a revised infrageneric classification of the genus and to investigate in more detail the systematics of New Caledonian species, we conducted molecular phylogenetic analyses using DNA sequence data for the nuclear ITS region on all samples, and for three chloroplast intergenic spacers (psbM-trnD, trnQ-rps16 and rps16-trnK) on a subset of our overall sampling. Our phylogenetic analyses are the most comprehensive to date for the genus, containing 111 biogeographically and morphologically diverse Garcinia species. The analyses support a broad circumscription of Garcinia, including several previously segregated genera (e.g. Allanblackia, Clusianthemum, Ochrocarpos p.p., Pentaphalangium, Rheedia, and Tripetalum). We recovered nine major clades falling within two major lineages, and we delimit 11 sections. We discuss each of the clades, assign them sectional names, discuss their distinguishing morphological features, compare our taxonomic treatment with the most recent sectional treatment, list representative species, note geographic distribution, and highlight some questions that deserve future investigations. We propose nine new nomenclatural combinations, four new names, and three new lectotypes. In New Caledonia (NC), a total of ten, all endemic, species are recognized and were included in our phylogenetic analyses, with several replicates per species (with the exception of G. virgata and G. urceolata, represented by a single accession each). New Caledonian species were retrieved within three separate clades, respectively including 1) G. balansae; 2) G. comptonii, G. neglecta, G. urceolata, G. virgata; and 3) G. amplexicaulis, G. densiflora, G. pedicellata, G. puat, G. vieillardii. Within NC, the phylogenies did not support the distinction between a putative undescribed species and G. balansae. However, it confirmed the distinction between NC species and both G. vitiensis (found in Fiji and Vanuatu) and G. adinantha (found in Fiji), suggesting that all NC species should be considered as endemics.

In a recent publication dealing with the sectional-level taxonomy of Garcinia, an illegitimate superfluous sectional name and two illegitimate homonyms were published. Herein we choose a legitimate sectional name, Garcinia section Rheediopsis Pierre, for the superfluous name Garcinia section Rheedia (L.) S.W.Jones ex P.W.Sweeney; and create two new legitimate names in Garcinia for Allanblackia gabonensis (Pellegr.) Bamps and A. parviflora A.Chev.

BACKGROUND AND AIMS:Progress in the systematic studies of the olive family (Oleaceae) during the last two decades provides the opportunity to update its backbone phylogeny and to investigate its historical biogeography. We also aimed to understand the factors underlying the disjunct distribution pattern between East Asia and both West Asia and Europe that is found more commonly in this family than in any other woody plant family. METHODS:Using a sampling of 298 species out of ~750, the largest in a phylogenetic study of Oleaceae thus far, with a set of 36 plastid and nuclear markers, we reconstructed and dated a new phylogenetic tree based on maximum likelihood and Bayesian methods and checked for any reticulation events. We also assessed the relative support of four competing hypotheses [Qinghai-Tibet Plateau uplift (QTP-only hypothesis); climatic fluctuations (climate-only hypothesis); combined effects of QTP uplift and climate (QTP-climate hypothesis); and no effects (null hypothesis)] in explaining these disjunct distributions. KEY RESULTS:We recovered all tribes and subtribes within Oleaceae as monophyletic, but uncertainty in the position of tribe Forsythieae remains. Based on this dataset, no reticulation event was detected. Our biogeographical analyses support the QTP-climate hypothesis as the likely main explanation for the East-West Eurasian disjunctions in Oleaceae. Our results also show an earlier origin of Oleaceae at ~86 Mya and the role of Tropical Asia as a main source of species dispersals. CONCLUSION:Our new family-wide and extensive phylogenetic tree highlights both the stable relationships within Oleaceae, including the polyphyly of the genus Chionanthus, and the need for further systematic studies within the largest and most undersampled genera of the family (Chionanthus and Jasminum). Increased sampling will also help to fine-tune biogeographical analyses across spatial scales and geological times.

Early natural historians-Comte de Buffon, von Humboldt, and De Candolle-established environment and ge-ography 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. 3500 species, we show that the water availability gradient from deserts to rain forests dictates turnover of lineages within continents across the tropics. We demonstrate that 95% of speciation occurs within a precipi-tation niche, showing profound phylogenetic niche conservatism, and that lineage turnover boundaries coin-cide with isohyets of precipitation. We reveal similar patterns on different continents, implying that evolution and dispersal follow universal processes.

Herbarium collections are an important source of dated, identified and preserved DNA, whose use in comparative genomics and phylogeography can shed light on the emergence and evolutionary history of plant pathogens. Here, we reconstruct 13 historical genomes of the bacterial crop pathogen Xanthomonas citri pv. citri (Xci) from infected Citrus herbarium specimens. Following authentication based on ancient DNA damage patterns, we compare them with a large set of modern genomes to estimate their phylogenetic relationships, pathogenicity-associated gene content and several evolutionary parameters. Our results indicate that Xci originated in Southern Asia ~11,500 years ago (perhaps in relation to Neolithic climate change and the development of agriculture) and diversified during the beginning of the 13th century, after Citrus diversification and before spreading to the rest of the world (probably via human-driven expansion of citriculture through early East-West trade and colonization).

Monodoreae (Annonaceae) is a tribe composed of 11 genera and 90 species restricted to the tropical African rain forests. All the genera are taxonomically well circumscribed except the species rich genera Uvariodendron and Uvariopsis which lack a recent taxonomic revision. Here, we used a robust phylogenomic approach, including all the 90 currently accepted species, with several specimens per species, and based on more than 300 Annonaceae-specific nuclear genes, to infer the phylogenetic tree of the Monodoreae and test the limits between the genera and species. We recover all the genera as monophyletic, except the genus Uvariopsis for which the species Uvariopsistripetala falls outside this clade. We thus reinstate the monotypic genus Dennettia for its single species Dennettiatripetala. We also erect a new tribe, Ophrypetaleae trib. nov., to accommodate the genera Ophrypetalum and Sanrafaelia, as we recover them excluded from the Monodoreae tribe with good support. Below the genus level, the genera Isolona, Monodora, Uvariastrum, Uvariodendron and Uvariopsis show weakly supported nodes and phylogenetic conflicts, suggesting that population level processes of evolution might occur in these clades. Our results also support, at the molecular level, the description of several new species of Uvariodendron and Uvariopsis, as well as several new synonymies. Finally, we present a taxonomic revision of the genera Dennettia, Uvariodendron and Uvariopsis, which contain one, 18 and 17 species respectively. We provide a key to the 11 genera of the Monodoraeae and describe four new species to science: Uvariodendronkimbozaense Dagallier & Couvreur, sp. nov., Uvariodendronmossambicense Robson ex Dagallier & Couvreur, sp. nov., Uvariodendronpilosicarpum Dagallier & Couvreur, sp. nov. and Uvariopsisoligocarpa Dagallier & Couvreur, sp. nov., and provide provisional descriptions of three putatively new species. We also present lectotypifications and nomenclatural changes implying synonymies and new combinations (Uvariodendroncitriodorum (Le Thomas) Dagallier & Couvreur, comb. et stat. nov., Uvariodendronfuscumvar.magnificum (Verdc.) Dagallier & Couvreur, comb. et stat. nov., Uvariopsiscongensisvar.angustifolia Dagallier & Couvreur, var. nov., Uvariopsisguineensisvar.globiflora (Keay) Dagallier & Couvreur, comb. et stat. nov., and Uvariopsissolheidiivar.letestui (Pellegr.) Dagallier & Couvreur, comb. et stat. nov.).