Isabel Larridon

• PhD
• Priority Leader Accelerated Taxonomy, RBG Kew at Royal Botanic Gardens, Kew

Mapania (Cyperaceae) is a pantropical genus associated with the forest understorey. Its evolutionary history and species delimitation are poorly known in Southeast Asia. To address this lack of knowledge, DNA sequence data from four chloroplast regions (trnL-F, atpH-F, psbA-trnH, and trnK-matK) were generated for a number of populations of 15 speci...

Image-based dried plant specimen identification poses a significant challenge due to the large number of possible classes and the extreme scarcity of labelled training samples. To tackle these limitations and mitigate classification biases, this research proposes a Particle Swarm Optimisation (PSO)-based weighted evolving ensemble model as well as...

Premise Magnoliids are a strongly supported clade of angiosperms. Previous phylogenetic studies based primarily on analyses of a limited number of mostly plastid markers have led to the current classification of magnoliids into four orders and 18 families. However, uncertainty remains regarding the placement of several families. Methods For the fi...

Grasses (Poaceae) comprise c . 11 800 species and are central to human livelihoods and terrestrial ecosystems. Knowing their relationships and evolutionary history is key to comparative research and crop breeding. Advances in genome‐scale sequencing allow for increased breadth and depth of phylogenomic analyses, making it possible to infer a new re...

Despite extensive research into the phylogenetic relationships of the genus Magnolia, Neotropical taxa have been neglected. This is partly because their numbers have recently doubled and now account for almost half of the global richness. Therefore, by sampling one-third of all Neotropical taxa their relationships were studied using morphological,...

Societal Impact Statement Biological samples and their associated information are an essential resource used by scientists, governments, policymakers, practitioners and communities to ensure that biodiversity can be appropriately protected and sustainably used. Yet, considering the enormous task of documenting the vast numbers of as‐yet‐unknown pla...

Premise Cleomaceae is an important model clade for studies of evolutionary processes including genome evolution, floral form diversification, and photosynthetic pathway evolution. Diversification and divergence patterns in Cleomaceae remain tangled as research has been restricted by its worldwide distribution, limited genetic sampling and species c...

Poster presentations 630 the endosperm (nourishing tissue in the seeds) often leads to triploid inviability, known as the triploid block, especially in inter-ploidy crosses between diploids and their tetraploid descendants. This phenomenon is frequently observed in mixed-ploidy plants. While the mechanistic basis of the triploid block has been docu...

This resource available in Zenodo includes several datasets: (1) Taxonomy (261 species): Updated taxonomy of the genus Scleria at the species level based on Bauters et al. 2016 and 2019. (2) Occurrences (latitude/longitude): data was compiled using observations from the Global Biodiversity Information Facility, Red List, research grade identifica...

New species to science are still being discovered and described, often from remote habitats. Madagascar is well known for its high species richness and exceptional levels of endemism across taxonomic groups. With an estimated 2,000 plant species still to be described from Madagascar, efforts are underway to gain better understanding of the Cyperace...

Scleria is a pantropical genus of annual and perennial herbs and the sixth largest genus in the Cyperaceae family with around 261 species. In this study, we produced preliminary extinction risk assessments for the ~30% of Scleria species that do not yet have a global Red List assessment and followed the Evolutionarily Distinct and Globally Endanger...

Grasses (Poaceae) comprise around 11,800 species and are central for human livelihoods and terrestrial ecosystems. Knowing their relationships and evolutionary history is key to comparative research and crop breeding. Advances in genome-scale sequencing allow for increased breadth and depth of phylogenomic analyses, making it possible to infer a ne...

Distephanus Cass. comprises 43 distinctive species of shrubs and small trees that have been placed historically within the ironweed tribe, Vernonieae (Asteraceae). Using the most expansive sampling of Distephanus to date, this study aims to test the monophyly of this genus and facilitate its classification. Molecular phylogenetic analyses were cond...

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundation...

Background and Aims Little is known about the response of ground layer plant communities to fire in Miombo ecosystems, which is a global blind spot of ecological understanding. We aimed: (1) to assess the impact of three experimentally imposed fire treatments on ground layer species composition and compare it with patterns observed for trees; and (...

Centauropsis is a genus of eight species in the family Compositae, all of which are endemic to Madagascar. There is almost no information about the pollen of this genus, with only one species having its pollen described to date, which hinders systematic studies involving this genus and closely related taxa. In this study, we comprehensively charact...

Premise Magnoliidae are a strongly supported clade of angiosperms. Previous phylogenetic studies based primarily on analyses of a limited number of mostly plastid markers have led to the current classification of magnoliids into four orders and 18 families. However, uncertainty remains regarding the placement of several families. Methods Here we p...

Tens of millions of images from biological collections have become available online over the last two decades. In parallel, there has been a dramatic increase in the capabilities of image analysis technologies, especially those involving machine learning and computer vision. While image analysis has become mainstream in consumer applications, it is...

Poales are one of the most species‐rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test six hypotheses regarding the evolution and assembly of Poales in open and closed habitats throughout the world, and examine whether diversification patterns demonstrate p...

What grows where? Knowledge about where to find particular species in nature must have been key to the survival of humans throughout our evolution. Over time, and as people colonised new land masses and habitats, interactions with the local biota led to a wealth of combined traditional and scientific wisdom about the distributions of species and th...

Poales are one of the most species-rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test the hypotheses that Poales species are assembled into distinct phyloregions, with centres of high phylogenetic diversity and endemism clustered in tropical regions, and t...

Background and aims – The rise of DNA sequencing in systematics has brought more understanding of the Cyperaceae family worldwide. Through these studies, it has been possible to delineate major clades and classify its species into subfamilies, tribes, and genera. Today, we have a good understanding of the species diversity and geographic distributi...

The Checklist of the Vascular Plants of the Republic of Guinea (CVPRG) is a specimen-based, expert-validated knowledge product, which provides a concise synthesis and overview of current knowledge on 3901 vascular plant species documented from Guinea (Conakry), West Africa, including their accepted names and synonyms, as well as their distribution...

Background and aims – Ochna holstii and its allies represent an ecologically important group in a variety of lowland to montane habitats in tropical eastern and southern Africa. Identifying and delimiting species within this group has proved challenging due to a lack of variation in morphological characters. We combine genomic-scale data of multipl...

The figwort family, Scrophulariaceae, comprises c. 2000 species whose evolutionary relationships at the tribal level have proven difficult to resolve, hindering our ability to understand their origin and diversification. We designed a specific probe kit for Scrophulariaceae, targeting 849 nuclear loci and obtaining plastid regions as by‐products. W...

Background and aims – The Cyperus margaritaceus-niveus complex is a group of ten tropical species from sub-Saharan Africa and Madagascar: C. karlschumannii , C. kibweanus , C. ledermannii , C. margaritaceus , C. niveus , C. nduru , C. obtusiflorus , C. somaliensis , C. sphaerocephalus , and C. tisserantii . They are characterised by a capitate head...

The angiosperm family Primulaceae is morphologically diverse and distributed nearly worldwide. However, phylogenetic uncertainty has obstructed the identification of major morphological and biogeographic transitions within the clade. We used target capture sequencing with the Angiosperms353 probes, taxon-sampling encompassing nearly all genera of t...

• Background and Aims: While variation in genome size and chromosome numbers and their consequences are often investigated in plants, the biological relevance of variation in chromosome size remains poorly known. Here, we examine genome and mean chromosome size in the cyperid clade (families Cyperaceae, Juncaceae, Thurniaceae), which is the largest...

A taxonomic study of Cyperus L. (Cyperaceae) in the Central-West region of Brazil is presented. We examined more than 1300 herbarium specimens. Many of the species were also studied in the field. Our results recognize 59 species of Cyperus in the Central-West of Brazil, including three species endemic to the country that are potentially threatened...

Aim Islands are ‘nature's laboratories of evolution’. Most island biogeographical studies have focussed on remote volcanic island chains. Here, we challenge island biogeographical patterns using a slowly evolving recent colonist present on five islands in a nonlinear chronosequence island chain. Location The Lesser Antilles (Caribbean). Taxon Mag...

Broˇzov´a et al. (2022) present a study, “Toward finally unraveling the phylogenetic relationships of Juncaceae with respect to another cyperid family, Cyperaceae”, with the premise of revising the phylogenetic re-lationships in Juncaceae and Cyperaceae based on Sanger sequencing of one nuclear rDNA (ITS) and two plastid regions (the gene rbcL and t...

Abstract: Tens of millions of images from biological collections have become available online in the last two decades. In parallel, there has been a dramatic increase in the capabilities of image analysis technologies, especially those involving machine learning and computer vision. Whilst image analysis has become mainstream in consumer applicatio...

Cyperus sect. Incurvi (Cyperaceae) contains 31 species worldwide, with important continental radiations in Australasia, Tropical Africa and Madagascar, and the Neotropics. Here, a monograph of the African and Madagascan species of Cyperus sect. Incurvi is presented, including descriptions, illustrations, synonymy, notes on habitat and ecology, geog...

Conservation action plans need to be devised and implemented if we are to reduce the extinction risk faced by globally threatened plants. However, most plant species categorized as threatened globally on the IUCN Red List lack conservation action plans. In West Africa, Guinea is one of the most diverse countries in terms of botanical species. In to...

An endemic species of Bulbostylis (Abildgaardieae, Cyperaceae) from Madagascar is described as new to science. Bulbostylis itremoensis is only known from two localities: the Itremo and Isalo massifs in the province of Fianarantsoa. The species can be recognised by its habit with numerous crowded culms, leaves and thick, soft roots with an outer myc...

This paper provides a linear classification of two subfamilies, 24 tribes, 10 subtribes and 95 genera of the monocot family Cyperaceae (Poales), based on a stable phylogenetic framework resulting from years of morphological, molecular phylogenetic and phylogenomic studies. The family includes c. 5687 species. The most species-rich tribes are the mo...

Chloroplast genomes are considered to be highly conserved. Nevertheless, differences in their sequences are an important source of phylogenetically informative data. Chloroplast genomes are increasingly applied in evolutionary studies of angiosperms, including Magnoliaceae. Recent studies have focused on resolving the previously debated classificat...

Best known as low maintenance houseplants, sansevierias are a diverse group of flowering plants native to Africa, Madagascar, the Arabian Peninsula, and the Indian subcontinent. Traditionally recognised as a distinct genus, Sansevieria was recently merged with the larger genus Dracaena based on molecular phylogenetic data. Within the Sansevieria Cl...

Mapanoioideae are one of two subfamilies of Cyperaceae and consist of 186 species. Molecular phylogenetic relationships in subfamily Cyperoideae have recently been studied well, whereas evolutionary relationships in Mapanioideae remain little known. Subfamily Mapanioideae include two tribes. This study focuses on Hypolytreae, which is represented b...

Advances in high-throughput DNA sequencing are allowing faster and more affordable generation of molecular phylogenetic trees for many organisms. However, resolving relationships at species level is still challenging, particularly for taxonomically difficult groups. Until recently, the classification of Ochna had been based only on morphological da...

Advances in high-throughput DNA sequencing are allowing faster and more affordable generation of molecular phylogenetic trees for many organisms. However, resolving relationships at species level is still challenging, particularly for taxonomically difficult groups. Until recently, the classification of Ochna had been based only on morphological da...

Landscape features impact gene flow and the spatial patterns of genetic variation between populations of a species. Because many Magnoliaceae species occur in fragmented and highly disturbed landscapes, the family provide an excellent model for landscape genetic studies. This research focuses on the subspecies and subpopulations of Magnolia cubensi...

The Caribbean islands provide an ideal setting for studying biodiversity, given their complex geological and environmental history, and their historical and current geographical proximity to the American mainland. Magnolia, a flagship tree genus that has 15 endemic and threatened taxa (12 species and 3 subspecies) on the Caribbean islands, offers a...

Cyperaceae subfamily Mapanioideae have reproductive units called spicoids, which are interpreted alternatively as flowers or partial inflorescence, and little is known about morphological variation of spicoids from an evolutionary perspective. Combining morphological and evolutionary analyses, we aimed to assess variation in spicoid morphology and...

Premise: Both universal and family-specific targeted sequencing probe kits are becoming widely used for reconstruction of phylogenetic relationships in angiosperms. Within the pantropical Ochnaceae, we show that with careful data filtering, universal kits are equally as capable in resolving intergeneric relationships as custom probe kits. Furtherm...

Cyperus prophyllatus, an endangered new species of Cyperus (Cyperaceae) from an aquatic ecosystem of the Atlantic Forest, Espírito Santo State, southeastern Brazil, is described and illustrated. The spikelet morphology of Cyperus prophyllatus is unique among the c. 950 species of Cyperus in having both a conspicuous spikelet prophyll and a corky ra...

Cyperaceae (sedges) are the third largest monocot family and are of considerable economic and ecological importance. Sedges represent an ideal model family to study evolutionary biology because of their species richness, global distribution, large discrepancies in lineage diversity, broad range of ecological preferences, and adaptations including m...

Landscape features impact gene flow and the spatial patterns of genetic variation between populations of a species. Because many Magnoliaceae species occur in fragmented and highly disturbed landscapes, the family is an excellent model for landscape genetic studies. This research focuses on the subspecies and localities of Magnolia cubensis and aim...

Generic delimitations in the Ficinia Clade of tribe Cypereae are revisited. In particular, we aim to establish the placement of annual species currently included in Isolepis of which the phylogenetic position is uncertain. Phylogenetic inference is based on two nuclear markers (ETS, ITS) and five plastid markers (the genes matK, ndhF, rbcL and rps1...

Molecular phylogenetic studies based on Sanger sequences have shown that Cyperaceae tribe Fuireneae s.l. is paraphyletic. However, taxonomic sampling in these studies has been poor, topologies have been inconsistent, and support for the backbone of trees has been weak. Moreover, uncertainty still surrounds the morphological limits of Schoenoplectie...

Aim: Madagascar is renowned for its unparalleled biodiversity and endemism. With many ecosystems under threat, research is urgently needed on its unique plant diversity. This applies both to Madagascar's forests and treeless vegetation types. Sedges (Cyperaceae) are among the top 10 species‐richest angiosperm families in Madagascar (310 native spec...

Sansevierias are a diverse group of flowering plants native to Africa, Madagascar, the Arabian Peninsula and the Indian subcontinent, popular outside their native range as low maintenance houseplants. Traditionally recognized as a distinct genus, Sansevieria was recently merged with the larger genus Dracaena based on molecular phylogenetic data. Wi...

Morphological characterizations of genera in Cyperaceae tribe Abildgaardieae have been highly problematic and the subject of much debate. Earlier molecular phylogenetic studies based on Sanger sequencing and a limited sampling have indicated that several generic circumscriptions are not monophyletic. Here, we provide the first phylogenetic hypothes...

Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para‐ or polyphyletic. Yet taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group here takes the position that the historical and continued use of subgenera and sections serves to (1) org...

Background and aims-Molecular phylogenetic studies have provided a clearer understanding of the complex relationships within the family Cyperaceae. These studies have consistently shown that 12 allied genera are nested in the genus Cyperus. However, early Sanger sequencing-based phylogenies that included the two species of the small South American...

Aim Colonization of new areas may entail shifts in diversification rates linked to biogeographical movement (dispersification), which may involve niche evolution if species were not exapted to new environments. Scleria (Cyperaceae) includes c. 250 species and has a pantropical distribution suggesting an extraordinary capacity for long‐distance dis...

Hybridisation has the potential to generate or homogenize biodiversity and is a particularly common phenomenon in plants, with an estimated 25% of plant species undergoing inter‐specific gene flow. However, hybridisation in Amazonia’s megadiverse tree flora was assumed to be extremely rare despite extensive sympatry between closely related species,...

The field of systematics is experiencing a new molecular revolution driven by the increased availability of high-throughput sequencing technologies. As these techniques become more affordable, the increased genomic resources have increasingly far-reaching implications for our understanding of the Tree of Life. With c. 2000 species, Carex (Cyperacea...

Mesanthemum is a genus comprising 16 species in the family Eriocaulaceae and is native to Africa and Madagascar. Eriocaulaceae are characterised by a basal tuft or rosette of narrow leaves and small flowers in heads. Mesanthemum can be recognised by diplostemonous flowers and fused glandular pistillate petals. While most Mesanthemum species are lar...

This pre-print is currently under consideration at Molecular Ecology. Hybridization has the potential to generate or homogenize biodiversity and is a particularly common phenomenon in plants, with an estimated 25% of species undergoing inter-specific gene flow. However, hybridization in Amazonia’s megadiverse tree flora was assumed to be extremely...

Genetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk. Such data are particularly important for species affected by habitat fragmentation such as Magnolia cubensis subsp. acunae , a Critically Endangered magnolia subspecies endemic to Cuba. Using genetic data from 6...

To achieve conservation success, we need to support the recovery of threatened species. Yet, <5% of plant species listed as threatened on the IUCN Red List have Species Conservation Action Plans (CAPs). If we are to move from a Red List to a Green List for threatened plant species, CAPs need to be devised and implemented. Guinea is one of the most...

In phylogenetic studies across angiosperms, at various taxonomic levels, polytomies have persisted despite efforts to resolve them by increasing sampling of taxa and loci. The large amount of genomic data now available and statistical tools to analyze them provide unprecedented power for phylogenetic inference. Targeted sequencing has emerged as a...

The generic placement of two African species currently included in the genus Fimbristylis, F. hygrophila and F. variegata, has been contentious. These two species, which have been known for the past half century, are glabrous tufted perennials whose spikelets have semi-distichous to spiral glume arrangement, bisexual flowers, and a pistil with an e...

Background-During the past decade several molecular phylogenetic studies tackled the complex relationships within tribe Cypereae. Based on these studies, previously accepted segregate genera such as Pycreus were sunk into the genus Cyperus. Recently, while revising the West African species of Cyperus, three taxa previously placed in Pycreus were id...

The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing...

A recent study included the genus Nemum into Bulbostylis. The combinations made for Nemum spadiceum and Nemum megastachyum resulted in illegitimate names. Here, the epithet of the homotypic name Scirpus briziformis is used to make nomenclaturally correct combinations for both subspecies of Nemum spadiceum in Bulbostylis. Furthermore, Bulbostylis br...

A taxonomic revision of the genus Scleria (Cyperoideae, Cyperaceae) in Madagascar is presented. Herbarium specimens have been examined and 422 identified to species level. Our results recognise 25 species of Scleria from Madagascar, plus an additional heterotypic variety. Eight species are endemic to Madagascar, two are near endemic, eight taxa are...

Eriocaulon is a genus of c. 470 aquatic and wetland species of the monocot plant family Eriocaulaceae. It is widely distributed in Africa, Asia and America, with centres of species richness in the tropics. Most species of Eriocaulon grow in wetlands although some inhabit shallow rivers and streams with an apparent adaptive morphology of elongated s...

Mischogyne (Annonaceae, tribe Monodoreae) is a genus of small- to medium-sized tropical trees and shrubs. It is characterised by a combination of: (1) stamens and carpels on a more or less extended torus; (2) carpels divergent from each other at the apex of the torus above the anthers; (3) anthers linear and anther connectives not expanded above th...

While the limits of Fimbristylis Vahl (1805: 285) are contentious (Goetghebeur & Coudijzer 1984, Gordon-Gray 1971, Lye 1971, 1973), particularly with regard to the inclusion of Abildgaardia Vahl (1805: 296) within Fimbristylis, all current data support the derivation of Crosslandia W.Fitzg. (1906: 9) from within Fimbristylis (Ghamkhar et al. 2007;...

Phylogenetic hypotheses and morphological characterizations of genera in the Abildgaardieae have suggested that current generic circumscriptions are not monophyletic. We here provide an updated phylogenetic hypothesis of the Abildgaardieae using nrDNA ITS sequences that continues to support the derivation of Nemum from within the Bulbostylis lineag...

Conservation Action Plan for Scleria guineensis, an endemic Cyperaceae species from Guinea.

A recent molecular phylogenetic study revealed four distinct evolutionary lineages in the genus Costularia s.l. (Schoeneae, Cyperaceae, Poales). Two lineages are part of the Oreobolus clade of tribe Schoeneae: the first being a much-reduced genus Costularia s.s., and the second a lineage endemic to New Caledonia for which a new genus Chamaedendron...

For Scleria subgen. Hypoporum, 214 species and infraspecific names were published since the first publication of the name Scleria. These names represent 76 accepted taxa, representing 72 species of Scleria subgen. Hypoporum. Herbarium material of all recognised species was studied, including the type material if available. Synonymy and typification...

• Background and Aim Quaternary glaciations strongly affected the distribution of species from arid and semiarid environments, as temperature drops were accompanied by strong fluctuations in rainfall. In this study, we examined the response of xerophytic species to glacial cycles, determining the genetic patterns and climatic niche of Echinopsis ch...

Copiapoa (Cactaceae) is a genus endemic to the Chilean Atacama Desert. The taxa of Copiapoa subsection Cinerei occur in an area of high species richness and high levels of species endemism of the Central Chilean biodiversity hotspot. Four taxa are usually recognised in this group: Copiapoa gigantea (sometimes placed in C. cinerea as C. cinerea subs...