Abstract Background Artemisia is a big genus of significant medicinal, ecological, and economic importance. However, a global sectional taxonomy with complete morphological and nomenclatural details is still lacking despite decades of research. Results Based on phylogenomic data (202 nuclear low copy genes plus two ribosomal DNA markers) covering 78% of accepted Artemisia species and morphological evidence (20 characters), we propose a global sectional taxonomy for the genus with morphological and nomenclatural details. This taxonomy accommodates 502 of the 505 accepted species (three remain unplaced owing to insufficient evidence) and recognizes 24 sections in eight subgenera, for which morphological descriptions, diagnostic keys, and nomenclatural acts are provided. Sixteen sections are newly established, and five are re-circumscribed. Conclusions This comprehensive sectional taxonomy establishes a robust framework for the infrageneric classification of Artemisia . It resolves long‑standing taxonomic uncertainties and provides a foundation for diverse research—from understanding the evolution and ecology of the genus to guiding the sustainable use of its medicinally and ecologically important species. Moreover, it presents a methodological case for addressing taxonomic complexity in other big plant genera.

The Nenets Autonomous Okrug (NAO), an Arctic region of European Russia, currently lacks a comprehensive checklist of vascular plants; its flora is the most species-poor among all first-level administrative units of the Russian Federation. As a baseline for this study, we compiled a list of 685 vascular plant taxa recorded within the NAO based on dot-distribution maps from “Flora of the North-East of the European Part of the USSR” (Tolmachev 1974–1977), subsequently publishing this as a GBIF-mediated dataset. The present contribution synthesises reliable data on an additional 113 species identified through references, digitised herbarium collections, and verified iNaturalist observations. Six of these taxa had not been previously reported for the NAO in any published references: four native species or hybrids (Potamogeton × nitens, Draba oxycarpa, Drosera × obovata, and Alchemilla transpolaris) and two alien species (Galeopsis bifida and Centaurea cyanus). We estimate vascular plant diversity of the NAO to be no fewer than 800 species (excluding apomictic microspecies).

Hypericum (Hypericaceae) is a large genus of flowering plants that contains approximately 500 species. In China, Hypericum is comprised of 13 sections, 76 species, and 9 subspecies, with at least 30 species that are used in traditional Chinese medicine. Despite its medicinal importance, only a few studies have focused on the molecular phylogenetic relationships of Hypericum within China. In this study, a total of 102 individuals representing 12 sections, 54 species, and 6 subspecies of Hypericum were sampled for phylogenetic analyses, using plastomes and nuclear ribosomal DNA datasets. These analyses constitute the first comprehensive molecular phylogenetic study of Hypericum from China. Phylogenetic analyses indicate that Hypericum is monophyletic and support the treatment of Triadenum and Lianthus as synonyms of Hypericum. Compared with traditionally defined sections based on morphological characteristics, only H. sect. Elodea, H. sect. Hirtella, H. sect. Monanthema, and H. sect. Trigynobrathys are monophyletic. Based on molecular and morphological evidence, we clarify the systematic position of H. elatoides, which is placed in H. sect. Roscyna. In addition, we observe that plastome data provide better resolution for infrageneric relationships within Hypericum than nrDNA sequences, and that the two datasets exhibit substantial cyto-nuclear discordance. This discordance is likely a result of both hybridization and suboptimal phylogenetic signal in the datasets used.

We present and discuss noteworthy floristic records obtained during the Moscow University summer expedition to Kyrgyzstan in 2016. Three taxa are reported as new for Kyrgyzstan: a native species (Utricularia australis R. Br.), an established alien (Artemisia verlotiorum Lamotte), and a nothospecies of local origin (Arctium × ambiguum (Čelak.) Nyman). Additionally, we document 31 species (26 native and 5 alien – Anthemis ruthenica M. Bieb., Atriplex oblongifolia Waldst. et Kit., Chenopodium vulvaria L., Lepidotheca suaveolens (Pursh) Nutt., and Medicago sativa L. s. l.) as new records for one of the seven floristic regions defined in the standard national checklist. These include 12 new records for Western Tian Shan, six for the Alay Valley, six for Inner Tian Shan, four for Fergana, three for the Ysyk-Köl Depression, and two for Northern Kyrgyzstan. Furthermore, we provide supplementary records for 12 species previously overlooked in the national checklist, supported by historical references and newly collected specimens.

Societal Impact Statement (EN) Cannabis has been used by humans for millennia, resulting in diverse landraces and uses. Its complex legal status and economic importance make sampling wild‐growing populations difficult, limiting past studies to modern cultivars with low genetic diversity. Our research provides crucial insights into the genetic diversity of wild‐growing and cultivated cannabis. We identified three major genetic groups—E Asia, Paleotropis, and Boreal—shedding light on evolutionary relationships within the genus. Understanding cannabis genetic structure supports conservation, sustainable breeding, and informed policy decisions. These findings lay a foundation for future research, ensuring the responsible use and preservation of this economically significant plant. Summary Cannabis has provided important and versatile services to humans for millennia. Domestication and subsequent dispersal have resulted in various landraces and cultivars. Unravelling the phylogeography of this genus poses considerable challenges because of its complex history. We relied on a Hyb‐Seq approach (combining target capture with shotgun sequencing), with the universal Angiosperms353 enrichment panel, to explore the genetic structure of wild‐growing cannabis accessions and cultivars by implementing phylogenomic and population genomic workflows on the same Hyb‐Seq data. Our findings support the treatment of Cannabis as a monotypic genus ( C. sativa L.), structured into three main genetic groups—E Asia, Paleotropis, and Boreal—with clear phylogeographic signal despite significant levels of admixture. The E Asia group was sister to the Paleotropis and the Boreal groups. Individuals within the Paleotropis group could be further structured into three subgroups: Iranian Plateau, C & S China and Himalayas, and Indoafrica. Individuals from the Boreal group split into two subgroups: Eurosiberia and W Mongolia and Caucasus and Mediterranean. Hemp and drug‐type landraces and cultivars consistently matched their putative geographic origin. These findings enhance our understanding of the genetic patterns in cannabis and provide a framework for future research into its current and past genetic diversity.

While 38% of tree species are at risk of extinction worldwide, their inventory and occurrence at ecologically and biogeographically meaningful scales is lacking in many parts of the world, including the biodiversity-rich Mediterranean region. Here, we provide presence/absence, extinction risk, biogeography and genetic diversity data of trees in 39 climatically and ecologically Mediterranean territories (so-called “botanical territories”) in North Africa, Western Asia and Southern Europe. The inventory includes 496 species and 147 subspecies from 50 families and 111 genera, including 48 species and 8 subspecies previously not considered as trees. We show that native tree species distribution is highly skewed across the tree of life with a few species-rich families such as the Rosaceae and the majority with less than 1% of all species. Endemism was not evenly distributed among botanical territories and neither was extinction risk, an assessment of which was lacking in almost half of the species. While no geographic trends were detectable, species richness was found to be positively correlated with botanical territory area and, when standardized by area, with habitat heterogeneity. Information on genetic diversity was lacking in two thirds of the species inventoried and mostly focused on species with economic importance. Our data are open access and can be used by researchers and stakeholders for a wide range of purposes, including conservation and restoration. Our findings identified major native tree richness hotspots as well as key knowledge gaps and biases related to extinction risk and genetic diversity. Our findings also emphasize the importance of increased collaboration to support the conservation of Mediterranean forest trees.

Abundance of established polyploid lineages varies across lineages, evolutionary time, and geography, suggesting both genetics and environment play a role in polyploid persistence. We show Arabidopsis lyrata is the most polyploid-rich species complex in the Arabidopsis genus, with multiple origins of autotetraploidy. This is revealed by genomic data from over 400 A. lyrata samples across Eurasia. We found over 30 previously undescribed autotetraploid populations in Siberia with a minimum of two separate origins, independent of those previously reported in Central Europe. The establishment of Siberian tetraploids is mediated by meiotic adaptation at the same genes as in European tetraploid A. lyrata and Arabidopsis arenosa, despite their genomic divergence and geographical separation. Haplotype analysis based on synthetic long-read assemblies supports the long-range introgression of adaptive alleles from the tetraploid interspecific pool of European A. lyrata and A. arenosa to tetraploid Siberian A. lyrata. Once adaptations to polyploidy emerge, they promote the establishment of new polyploid lineages through adaptive inter- and intraspecific introgression.

Widely distributed plant genera offer insights into biogeographic processes and biodiversity. The Carduus-Cirsium group, with over 600 species in eight genera, is diverse across the Holarctic regions, especially in the Mediterranean Basin, Southwest Asia, Japan, and North America. Despite this diversity, evolutionary and biogeographic processes within the group, particularly for the genus Cirsium, remain underexplored. This study examines the biogeographic history and diversification of the group, focusing on Cirsium, using the largest molecular dataset for the group (299 plants from 251 taxa). Phylogenomic analyses based on 350 nuclear loci, derived from target capture sequencing, revealed highly resolved and consistent phylogenetic trees, with some incongruences likely due to hybridization and incomplete lineage sorting. Ancestral range estimations suggest that the Carduus-Cirsium group originated during the Late Miocene in the Western Palearctic, particularly in the Mediterranean, Eastern Europe, or Southwest Asia. A key dispersal event to tropical eastern Africa around 10.7 million years ago led to the genera Afrocarduus and Afrocirsium, which later diversified in the Afromontane region. The two subgenera of Cirsium-Lophiolepis and Cirsium-began diversifying around 7.2-7.3 million years ago in the Western Palearctic. During the Early Pliocene, diversification rates increased, with both subgenera dispersing to Southwest Asia, where extensive in situ diversification occurred. Rapid radiations in North America and Japan during the Pleistocene were triggered by jump-dispersals events from Asia, likely driven by geographic isolation and ecological specialization. This added further layers of complexity to the already challenging taxonomic classification of Cirsium.Keywords: Biogeography; Carduinae; Cirsium; Diversification; North Hemisphere; Target-enrichment; Taxonomy.

Artemisia transbaicalensis Leonova, a species widely accepted in important biodiversity databases, is shown to be conspecific with A. tanacetifolia Linnaeus based on the evidence from morphology and geography.

Developing robust phylogenies and comprehensive taxonomies for big plant genera is crucial for unlocking plant-derived solutions to global sustainability challenges. Artemisia, a big genus comprising ~500 species, holds immense medicinal and ecological importance. Despite decades of efforts, establishing a comprehensive phylogeny and taxonomy for global Artemisia has remained a formidable challenge. Here, we reconstruct the most comprehensive phylogeny of global Artemisia to date (394 species) using a gigamatrix approach. We also analyze evolutionary patterns of 20 morphological characters of Artemisia worldwide to evaluate their taxonomic utility. Based on these findings, we propose a global taxonomy for Artemisia, recognizing 24 sections in 8 subgenera, and placing 99.6% of accepted species (502/505). This study provides a robust framework to advance understanding of the evolution and ecology of Artemisia, and to promote the sustainable utilization of its rich resources. Meanwhile, it introduces an exemplary case for taxonomic research on big genera in the genomic era.

Ajaniopsis is a monotypic genus of Asteraceae endemic to the Tibetan Plateau, growing on alpine scree slopes. It has been widely recognized as a separate genus and employed in many evolutionary and ecological analyses for its unique morphological characters. Despite being treated as an endangered species and once included in lists of key protected plant species, its systematic position has never been critically evaluated in a phylogenetic context. Furthermore, neither its past nor future distributional range has been assessed or predicted. In this study, we undertook morphological and molecular investigations to elucidate its systematics, and employed niche modeling to evaluate its historical, current, and potential future distributional range. Our phylogenetic analyses, based on the plastid genome and two nuclear DNA regions, show that Ajaniopsis is deeply nested in the mega-diverse genus Artemisia. Morphological analysis indicates that its unique characters are also present in many distantly related species of Artemisia, implying significant convergent evolution. Consequently, Ajaniopsis can be reduced into Artemisia rather than being considered a distinct genus. Niche modeling reveals that its distributional range underwent a dramatic contraction ca. 3.3 Ma and is likely to continue shrinking in the future. This dramatic range contraction might be associated with climate changes and human activities in its unique habitat. Therefore, immediate in situ conservation is imperative for this critically endangered species, necessitating the establishment of a nature reserve on the Tibetan Plateau. Our studies highlight that it is beneficial to explore the evolutionary history of endangered species in detail when drafting conservation strategies.

AbstractAbundance of polyploidy varies across lineages, evolutionary time and geography, suggesting both genetics and environment play a role in polyploid persistence.Arabidopsis lyrataappears to be the most polyploidy-rich species-complex in theArabidopsisgenus, with multiple origins of autotetraploidy. This is revealed by genomic data from over 400 samples across Eurasia. We found over 30 previously undescribed autotetraploid populations in Siberia with a minimum of two separate origins, independent of those previously reported in Central Europe. The establishment of Siberian tetraploids is mediated by meiotic adaptation at the same genes as in European tetraploidA. lyrataandArabidopsis arenosa,despite high divergence and geographical separation. Haplotype analysis based on synthetic long-read assemblies supports the long-range introgression of adaptive alleles from the tetraploid interspecific pool of EuropeanA. lyrataandA. arenosato tetraploid SiberianA. lyrata. Once evolved, adaptation to polyploidy promotes the establishment of new polyploid lineages through adaptive inter– and intraspecific introgression.

For the purpose of the Atlas of the Russian Flora production, we converted data from floristic checklists published in 636 sources from 1975 to 2023 into e-form. We gave preference to complete floristic checklists, however for some areas with low data density partial lists, route records, vegetation relevés and reviews, and in some cases, scattered publications with floristic records also served as data sources. As of April 4, 2024, the Local Floras of Russia dataset (doi: 10.15468/rxtjt2) contains 682,130 plant records from 3,297 geographic locations. The geographic coordinates and georeferencing accuracy are indicated for all species within each floristic list. The average georeferencing accuracy is 28 km. Open access to the database is provided through the GBIF, which allows users to download it either as a whole or in parts, in tabular form. New sources are continuously incorporated into the database.

Cannabis has provided important and versatile services to humans for millennia. Domestication and subsequent dispersal have resulted in various landraces and cultivars. Unravelling the phylogeography of this genus poses considerable challenges due to its complex history. We relied on a Hyb-Seq approach (combining target capture with shotgun sequencing), with the universal Angiosperms353 enrichment panel, to explore the genetic structure of wild-growing accessions and cultivars by implementing phylogenomic and population genomic workflows on the same Hyb-Seq data. Our findings support the treatment of Cannabis as a monotypic genus ( C. sativa L.), structured into three main genetic groups (E Asia, Paleotropis, and Boreal) with clear phylogeographic signal despite significant levels of admixture. The E Asia group was sister to the Paleotropis and the Boreal groups. Individuals within the Paleotropis group could be further structured into three subgroups: Iranian Plateau, C & S China and Himalayas, and Indoafrica. Individuals from the Boreal group split into two subgroups: Eurosiberia and W Mongolia and Caucasus and Mediterranean. Hemp and drug-type landraces and cultivars consistently matched their putative geographic origin. These findings enhance our understanding of the genetic patterns in Cannabis and provide a framework for future research into its current and past genetic diversity. ### Competing Interest Statement The authors have declared no competing interest.

Abstract For many arctic species, the spatial (re‐)colonization patterns after the last Pleistocene glaciation have been described. However, the temporal aspects of their colonization are largely missing. Did one route prevail early, while another was more important later? The high Arctic archipelago Svalbard represents a good model system to address timeframe of postglacial plant colonization. Svalbard was almost fully glaciated during last glacial maximum and (re‐)colonization of vascular plants began in early Holocene. Early Holocene climatic optimum (HCO) supported an expanded establishment of a partly thermophilic vegetation. Today, we find remnants of this vegetation in sheltered regions referred to as “Arctic biodiversity hotspots”. The oldest record of postglacial plant colonization to Svalbard is found in Ringhorndalen‐Flatøyrdalen. Even though thermophilic species could establish also later in Holocene, only HCO was favorable for vast colonization, and only hotspots offered stable conditions for thermophilic populations throughout Holocene. Thus, these relic populations may reflect colonization patterns of HCO. We investigate whether the colonization direction of thermophilic plants (Arnica angustifolia, Campanula uniflora, Pinguicula alpina, Tofieldia pusilla, and Vaccinium uliginosum ssp. microphyllum) in Ringhorndalen‐Flatøyrdalen was uniform and different from later colonization events in other localities and non‐thermophilic plants (Arenaria humifusa, Bistorta vivipara, Juncus biglumis, Oxyria digyna, and Silene acaulis). We analyzed plastid haplotypes of the 10 taxa from Ringhorndalen‐Flatøyrdalen, from later‐colonized localities in Svalbard, and from putative source regions outside Svalbard. Only rare and thermophilic taxa Campanula uniflora and Vaccinium uliginosum ssp. microphyllum provided results suggesting at least two colonization events from different source regions. Tofieldia pusilla and all the non‐thermophilic plants showed no clear phylogeographically differentiation within Svalbard. Two of the thermophilic species showed no sequence variation. Based on the results, a uniform colonization direction to Svalbard in early Holocene is not probable; several source areas and dispersal directions were contemporarily involved.

A transition to selfing can be beneficial when mating partners are scarce, for example, due to ploidy changes or at species range edges. Here, we explain how self-compatibility evolved in diploid Siberian Arabidopsis lyrata, and how it contributed to the establishment of allotetraploid Arabidopsis kamchatica. First, we provide chromosome-level genome assemblies for two self-fertilizing diploid A. lyrata accessions, one from North America and one from Siberia, including a fully assembled S-locus for the latter. We then propose a sequence of events leading to the loss of self-incompatibility in Siberian A. lyrata, date this independent transition to ∼90 Kya, and infer evolutionary relationships between Siberian and North American A. lyrata, showing an independent transition to selfing in Siberia. Finally, we provide evidence that this selfing Siberian A. lyrata lineage contributed to the formation of the allotetraploid A. kamchatica and propose that the selfing of the latter is mediated by the loss-of-function mutation in a dominant S-allele inherited from A. lyrata.

Digitisation of the Moscow University Herbarium (MW) was started in the spring of 2015. Since October 2016, we have been publishing the images of specimens on the portal of the Moscow Digital Herbarium (https://plant.depo.msu.ru/) in open access mode. Gradually, we started to publish extended metadata on our portal, like full transcriptions of labels and georeferences, i.e. the coordinates of collection sites for each specimen. As of January, 14, 2023, two thirds of the specimens of the Moscow University Herbarium (693168 specimens, or 66%) are georeferenced, while 359593 specimens are still in work. The article describes the geodata of the Moscow University Herbarium both in the geographical aspect (data coverage for different regions) and in the aspect of georeferencing accuracy. General guidelines for georeferencing herbarium collections are given.