The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity

Macroevolution of the plant-hummingbird pollination system

Plant-hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant-hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre-dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build-up of both diversities coinciding temporally, and hence suggesting co-diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species-level interaction data in macroevolutionary studies.

Genome size is positively correlated with extinction risk in herbaceous angiosperms

Angiosperms with large genomes experience nuclear-, cellular-, and organism-level constraints that may limit their phenotypic plasticity and ecological niche, which could increase their risk of extinction. Therefore, we test the hypotheses that large-genomed species are more likely to be threatened with extinction than those with small genomes, and that the effect of genome size varies across three selected covariates: life form, endemism, and climatic zone. We collated genome size and extinction risk information for a representative sample of angiosperms comprising 3250 species, which we analyzed alongside life form, endemism, and climatic zone variables using a phylogenetic framework. Genome size is positively correlated with extinction risk, a pattern driven by a signal in herbaceous but not woody species, regardless of climate and endemism. The influence of genome size is stronger in endemic herbaceous species, but is relatively homogenous across different climates. Beyond its indirect link via endemism and climate, genome size is associated with extinction risk directly and significantly. Genome size may serve as a proxy for difficult-to-measure parameters associated with resilience and vulnerability in herbaceous angiosperms. Therefore, it merits further exploration as a useful biological attribute for understanding intrinsic extinction risk and augmenting plant conservation efforts.

Island biogeography of the megadiverse plant family Asteraceae

The megadiverse plant family Asteraceae forms an iconic component of island floras including many spectacular radiations, but a global picture of its insular diversity is lacking. Here, we uncover the global biogeographical and evolutionary patterns of Asteraceae on islands to reveal the magnitude and potential causes of their evolutionary success. We compile a global checklist of Asteraceae species native and endemic to islands and combine it with macroecological analyses and a phylogenetic review of island radiations. Asteraceae have a global distribution on islands, comprising approximately 6,000 native island species, with 58% endemics. While diversity of the family on islands is lower than expected given its overall diversity, Asteraceae are the most diverse family on oceanic islands, suggesting an exceptional ability to thrive in isolation. In agreement with island biogeography predictions, native Asteraceae diversity increases with area and decreases with isolation, while endemism increases with both. We identify 39 confirmed island radiations and 69 putative radiations, exceeding numbers for other iconic insular groups. Our results reveal Asteraceae offer immense potential for research in ecology and evolution, given their close tracking of island biogeography expectations, large number of both species and radiations, cosmopolitan distribution, and numerous undiscovered radiations.

Predicting undetected native vascular plant diversity at a global scale

Vascular plants are diverse and a major component of terrestrial ecosystems, yet their geographic distributions remain incomplete. Here, I present a global database of vascular plant distributions by integrating species distribution models calibrated to species' dispersal ability and natural habitats to predict native range maps for 201,681 vascular plant species into unsurveyed areas. Using these maps, I uncover unique patterns of native vascular plant diversity, endemism, and phylogenetic diversity revealing hotspots in underdocumented biodiversity-rich regions. These hotspots, based on detailed species-level maps, show a pronounced latitudinal gradient, strongly supporting the theory of increasing diversity toward the equator. I trained random forest models to extrapolate diversity patterns under unbiased global sampling and identify overlaps with modeled estimations but unveiled cryptic hotspots that were not captured by modeled estimations. Only 29% to 36% of extrapolated plant hotspots are inside protected areas, leaving more than 60% outside and vulnerable. However, the unprotected hotspots harbor species with unique attributes that make them good candidates for conservation prioritization.

Plant diversity darkspots for global collection priorities

More than 15% of all vascular plant species may remain scientifically undescribed, and many of the > 350 000 described species have no or few geographic records documenting their distribution. Identifying and understanding taxonomic and geographic knowledge shortfalls is key to prioritising future collection and conservation efforts. Using extensive data for 343 523 vascular plant species and time-to-event analyses, we conducted multiple tests related to plant taxonomic and geographic data shortfalls, and identified 33 global diversity darkspots (those 'botanical countries' predicted to contain most undescribed and not yet recorded species). We defined priority regions for future collection according to several socio-economic and environmental scenarios. Most plant diversity darkspots are found within global biodiversity hotspots, with the exception of New Guinea. We identify Colombia, Myanmar, New Guinea, Peru, Philippines and Turkey as global collection priorities under all environmental and socio-economic conditions considered. Our study provides a flexible framework to help accelerate the documentation of global plant diversity for the implementation of conservation actions. As digitisation of the world's herbaria progresses, collection and conservation priorities may soon be identifiable at finer scales.

The complete chloroplast genome of Typha angustifolia and its phylogenetic position in Typhaceae

Typha angustifolia, commonly known as narrowleaf cattail, is a marginal, semi-aquatic, herbaceous perennial species with both ecological and edible values. In this study, the complete chloroplast (cp) genome of T. angustifolia was assembled using the next-generation sequencing technology. The whole cp genome was 161,597 bp in length, consisting of a large single copy (LSC, 89,119 bp) and a small single copy (SSC, 18,550 bp) separated by two copies of inverted region (IR, 26,964 bp). The genome encoded 113 unique genes, including 79 protein-coding genes, 30 tRNA genes, four rRNA genes, with 19 duplicated genes in the IR regions. Phylogenetic analysis showed that T. angustifolia is sister to Typha orientalis in the family Typhaceae. The cp genome of T. angustifolia is reported for the first time, which will provide essential and important genetic resources for future phylogenetic investigation within the genus Typha.

Expression of a single-chain monellin (MNEI) mutant with enhanced stability in transgenic mice milk

Monellin is a sweet protein that may be used as a safe and healthy sweetener. However, due to its low stability, the application of monellin is currently very limited. Here, we describe a wild-type, a double-sites mutant (E2N/E23A) and a triple-sites mutant (N14A/E23Q/S76Y) of single-chain monellin (MNEI) expressed in transgenic mice milk. Based on enzyme-linked immunoassay (ELISA), Western blot, and sweetness intensity testing, their sweetness and stability were compared. After boiling for 2 min at different pH conditions (2.5, 5.1, 6.8, and 8.2), N14A/E23Q/S76Y-MNEI showed significantly higher sweetness and stability than the wild-type and E2N/E23A-MNEI. These results suggest that N14A/E23Q/S76Y-MNEI shows remarkable potential as a sweetener in the future.

Resource dilution effect rather than resource concentration hypothesis explains the patterns of pre-dispersal seed predation of an African cycad along an elevational gradient in South Africa

The genus Encephalartos is entirely endemic to Africa, and like most cycad species, the genus is at risk of extinction. One of the threats jeopardising the future of the genus is reproduction failure, a failure that is still poorly understood. Our objective was to investigate what predisposes Encephalartos species to seed damages through predation, a potential cause of reproduction failure. We collected functional traits of 430 individuals of Encephalartos villosus, as well as data on pre-dispersal seed predation, habitat type and elevation in the Origi Gorge Nature Reserve, South Africa. Then, we analysed our data by fitting a structural equation model. We found that plants tend to be taller when moving from open to close habitat, whereas plant height tends to increase along elevation. In addition, taller plants tend to have more leaves, and plant canopy size shows significant positive relationship with elevation, plant height and number of leaves. These findings suggest a leaf height-canopy dimension strategy perhaps in response to environmental stresses imposed by elevation. We tested the effects of habitat types on seed production. Although there were significantly more seeds in open habitats, open habitats showed the lowest proportion of predated seeds. Finally, we tested the effects of elevation on seed production. We found that seed production decreases along elevation while the proportion of predated seeds increases. Under the resource concentration hypothesis, these findings (where there are more resources, predation is low) are unexpected, suggesting rather that it is the resource dilution effect that matches the pre-dispersal seed predation patterns in our study area. We suggest that anthropogenic pressures at lower elevation due to easy access may cause seed predators to shift towards higher elevation where they cause heavier damage to seed, thus perhaps contributing to the extinction risk of the genus Encephalartos.

Phylogenomics of mulberries (Morus, Moraceae) inferred from plastomes and single copy nuclear genes

Mulberries (genus Morus), belonging to the order Rosales, family Moraceae, are important woody plants due to their economic values in sericulture, as well as for nutritional benefits and medicinal values. However, the taxonomy and phylogeny of Morus, especially for the Asian species, remains challenging due to its wide geographical distribution, morphological plasticity, and interspecific hybridization. To better understand the evolutionary history of Morus, we combined plastomes and a large-scale nuclear gene analyses to investigate their phylogenetic relationships. We assembled the plastomes and screened 211 single-copy nuclear genes from 13 Morus species and related taxa. The plastomes of Morus species were relatively conserved in terms of genome size, gene content, synteny, IR boundary and codon usage. Using nuclear data, our results elucidated identical topologies based on coalescent and concatenation methods. The genus Morus was supported as monophyletic, with M. notabilis as the first diverging lineage and the two North American Morus species, M. microphylla and M. rubra, as sister to the other Asian species. In the Asian Morus species, interspecific relationships were completely resolved. However, cyto-nuclear discordances and gene tree-species tree conflicts were detected in the phylogenies of Morus, with multiple evidences supporting hybridization/introgression as the main cause of discordances between nuclear and plastid phylogenies, while gene tree-species tree conflicts were mainly caused by ILS.

The Tropical Andes Biodiversity Hotspot: A Comprehensive Dataset for the Mira-Mataje Binational Basins

We present a flora and fauna dataset for the Mira-Mataje binational basins. This is an area shared between southwestern Colombia and northwestern Ecuador, where both the Chocó and Tropical Andes biodiversity hotspots converge. We systematized data from 120 sources in the Darwin Core Archive (DwC-A) standard and geospatial vector data format for geographic information systems (GIS) (shapefiles). Sources included natural history museums, published literature, and citizen science repositories across 13 countries. The resulting database has 33,460 records from 6,821 species, of which 540 have been recorded as endemic, and 612 as threatened. The diversity represented in the dataset is equivalent to 10% of the total plant species and 26% of the total terrestrial vertebrate species in both hotspots. The dataset can be used to estimate and compare biodiversity patterns with environmental parameters and provide value to ecosystems, ecoregions, and protected areas. The dataset is a baseline for future assessments of biodiversity in the face of environmental degradation, climate change, and accelerated extinction processes.

Phytochemical analysis and biological evaluation of essential oils and extracts from Heracleum pastinacifolium subsp. incanum (Boiss. & A.Huet) P.H.Davis, an endemic plant from Turkey

Essential oil content of and phenolic compounds flower-fruit, root, and aerial parts of Heracleum pastinacifolium subsp. incanum were analysed by GC/MS and LC/MS methods, respectively. Antidiabetic, anticholinesterase, and antioxidant activities of flower-fruit, root, aerial parts methanol extracts were evaluated. Apiole (35.0%), myristicine (72.2%), and myristicine (15.1%) were found as major compounds of fruit-flower mixture, root, aerial part essential oils, respectively. Hesperidin was found the highest amount in aerial part and flower-fruit extracts with 8904.2621 ng/mL and 11558.3634 ng/mL values, respectively. Fruit-flower extract showed the highest activity against α-glucosidase (24%). Root extract demonstrating the highest activity (18%) against AChE enzyme. Flowers-fruits mixture methanol extract had a higher % inhibition value on ABTS·+ and DPPH•. Flowers-fruits mixture methanol extract was rich in total phenol, total tannin, and protein content. All the extracts were determined as genetoxically safe according to the results of Ames/Salmonella, Escherichia coli WP2 and Allium cepa assays.

Disturbance and vegetational structure in an urban forest of Indian Siwaliks: an ecological assessment

Urban forests face multiple human-mediated pressures leading to compromised ecosystem structure and functioning. Therefore, understanding ecosystem structure in response to ongoing pressures is crucial for sustaining ecological integrity and human well-being. We aim to assess the disturbance and its effects on the vegetation structure of urban forests in Chandigarh using a combination of remote sensing techniques and vegetation surveys. The disturbance was evaluated as a change in NDVI (Normalised Difference Vegetation Index) from 2001 to 2021 by applying the BFAST (Breaks For Additive Season and Trend) algorithm to the MODIS satellite imagery data. A vegetation survey was conducted to compare the species composition, taxonomic and phylogenetic diversity as measures of forest vegetational structure. While signals of disturbance were evident, the changes in vegetation structure were not well established from our study. Further, this analysis indicated no significant differences in vegetation composition due to disturbance (F1,12 = 0.91, p = 0.575). However, the phylogenetic diversity was substantially lower for disturbed plots than undisturbed plots, though the taxonomic diversity was similar among the disturbed and undisturbed plots. Our results confirmed that disturbance effects are more prominent on the phylogenetic than taxonomic diversity. These findings can be considered early signals of disturbance and its impact on the vegetation structure of urban forests and contribute to the knowledge base on urban ecosystems. Our study has implications for facilitating evidence-based decision-making and the development of sustainable management strategies for urban forest ecosystems.

O armário: Fruiting phenology data for 4,462 plant taxa in Portugal (1926-2013)

Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. Here we provide information on the exact date and site where seeds of 4,462 taxa were collected for the Index Seminum (seed exchange catalogue) of the Botanic Garden of the University of Coimbra, between 1926 and 2013. Seeds were collected from spontaneous and cultivated individuals across Portugal, including both native and introduced taxa. The database consists of 127,747 curated records with information on the species, or infraspecific taxa (including authority), and the day and site where seeds were collected. All records are georeferenced and provided with a confidence interval for the collection site. Taxonomy was first curated manually by in-house botanists and then harmonized according to the GBIF backbone taxonomy.

Zygomorphic flowers last longer: the evolution of floral symmetry and floral longevity

Floral longevity, the length of time a flower remains open and functional, is a phylogenetically conserved trait that balances floral costs against the rate at which flowers are pollinated. Floral symmetry has long been considered a key trait in floral evolution. Although zygomorphic (bilaterally symmetric) flowers typically receive fewer floral visitors than actinomorphic (radially symmetric) flowers, it is yet to be determined whether this could be associated with longer floral longevity. Using newly collected field data combined with data from the literature on 1452 species in 168 families, we assess whether floral longevity covaries with floral symmetry in a phylogenetic framework. We find that zygomorphic flowers last on average 1.1 days longer than actinomorphic flowers, a 26.5% increase in longevity, with considerable variation across both groups. Our results provide a basis to discuss the ecological and evolutionary costs of zygomorphy for plants. Despite these costs, zygomorphy has evolved numerous times throughout angiosperm history, and we discuss which rewards may outweigh the costs of slower pollination in zygomorphic flowers.

Previously unmeasured genetic diversity explains part of Lewontin's paradox in a k-mer-based meta-analysis of 112 plant species

At the molecular level, most evolution is expected to be neutral. A key prediction of this expectation is that the level of genetic diversity in a population should scale with population size. However, as was noted by Richard Lewontin in 1974 and reaffirmed by later studies, the slope of the population size-diversity relationship in nature is much weaker than expected under neutral theory. We hypothesize that one contributor to this paradox is that current methods relying on single nucleotide polymorphisms (SNPs) called from aligning short reads to a reference genome underestimate levels of genetic diversity in many species. To test this idea, we calculated nucleotide diversity ( π ) and k-mer-based metrics of genetic diversity across 112 plant species, amounting to over 205 terabases of DNA sequencing data from 27,488 individual plants. We then compared how these different metrics correlated with proxies of population size that account for both range size and population density variation across species. We found that our population size proxies scaled anywhere from about 3 to over 20 times faster with k-mer diversity than nucleotide diversity after adjusting for evolutionary history, mating system, life cycle habit, cultivation status, and invasiveness. The relationship between k-mer diversity and population size proxies also remains significant after correcting for genome size, whereas the analogous relationship for nucleotide diversity does not. These results suggest that variation not captured by common SNP-based analyses explains part of Lewontin's paradox in plants.

Trends in botanical exploration in Nigeria forecast over 1000 yet undescribed vascular plant species

BACKGROUND AND AIMS

Taxonomists are primary actors of biodiversity assessment. At the same time, there is awareness by the taxonomic community at large that the field is going through a crisis, sometimes referred to as the 'taxonomic impediment'. Coupled with the ongoing biodiversity crisis, or 6th mass extinction, this biodiversity impedance puts at risk the target set in the Convention on Biological Diversity's (CBD) Global Biodiversity Framework vision 2050, which calls for urgent action to '… put biodiversity on a path to recovery by 2030 for the benefit of planet and people'. This risk is particularly pronounced in tropical African countries where taxonomic studies are done on an ad hoc basis. In this study, our aim is to investigate the historical trends in botanical exploration of vascular plants in Nigeria and forecast the near-term (50-year) description of presently unknown species, which we use to discuss scenarios of taxonomic effort that may be necessary for a comprehensive biodiversity assessment in the country.

METHODS

The study is based on a dataset from the World Checklist of Vascular Plants, containing all vascular plant species reported to occur in Nigeria. We fit nested Bayesian time series regressions to estimate the long-term trend in the rate of description of vascular plant species in Nigeria. From these models, we use an ensemble forecast to estimate the number of species descriptions by the year 2070, and then evaluate the description rates per taxonomist required to meet this estimate under different totals of active taxonomists.

KEY RESULTS

We find a striking difference in species description between Nigerian botanists and their foreign counterparts, with the former contributing relatively small numbers. Additionally, only a fraction of the authors involved in describing Nigeria's vascular plants are of indigenous origin. Our study reveals that the number of new species described annually exhibits a long-term increasing trend, with an average of 19.5 species described per year. However, after taking into account year-to-year variability and the number of taxonomists active in a given year, the long-term trend in species descriptions credibly declines over time. While the number of authors involved in describing species has generally increased over time, it has remained stable since the 1950s. Predictions for the number of new species descriptions by 2070 vary by model, with an ensemble prediction estimating 1140 species descriptions, but ranging from 1004 to 2239 between individual models.

CONCLUSIONS

The study estimates that current levels of taxonomic activity should lead to a 20 % increase in known species of vascular plants in Nigeria over the next 50 years, which is still probably an underestimate of the true, unknown species richness. Urgent action is needed to address the taxonomic impediment so that local taxonomic studies in tropical African countries can achieve the CBD's Global Biodiversity Framework vision 2050. Here, we outline some key pathways to achieving this goal.

Phylogenomic analysis reveals five independently evolved African forage grass clades in the genus Urochloa

BACKGROUND AND AIMS

The grass genus Urochloa (Brachiaria) sensu lato includes forage crops that are important for beef and dairy industries in tropical and sub-tropical Africa, South America and Oceania/Australia. Economically important species include U. brizantha, U. decumbens, U. humidicola, U. mutica, U. arrecta, U. trichopus, U. mosambicensis and Megathyrsus maximus, all native to the African continent. Perennial growth habits, large, fast growing palatable leaves, intra- and interspecific morphological variability, apomictic reproductive systems and frequent polyploidy are widely shared within the genus. The combination of these traits probably favoured the selection for forage domestication and weediness, but trait emergence across Urochloa cannot be modelled, as a robust phylogenetic assessment of the genus has not been conducted. We aim to produce a phylogeny for Urochloa that includes all important forage species, and identify their closest wild relatives (crop wild relatives). Finally, we will use our phylogeny and available trait data to infer the ancestral states of important forage traits across Urochloa s.l. and model the evolution of forage syndromes across the genus.

METHODS

Using a target enrichment sequencing approach (Angiosperm 353), we inferred a species-level phylogeny for Urochloa s.l., encompassing 54 species (~40 % of the genus) and outgroups. Phylogenies were inferred using a multispecies coalescent model and maximum likelihood method. We determined the phylogenetic placement of agriculturally important species and identified their closest wild relatives, or crop wild relatives, based on well-supported monophyly. Further, we mapped key traits associated with Urochloa forage crops to the species tree and estimated ancestral states for forage traits along branch lengths for continuous traits and at ancestral nodes in discrete traits.

KEY RESULTS

Agricultural species belong to five independent clades, including U. brizantha and U. decumbens lying in a previously defined species complex. Crop wild relatives were identified for these clades supporting previous sub-generic groupings in Urochloa based on morphology. Using ancestral trait estimation models, we find that five morphological traits that correlate with forage potential (perennial growth habits, culm height, leaf size, a winged rachis and large seeds) independently evolved in forage clades.

CONCLUSIONS

Urochloa s.l. is a highly diverse genus that contains numerous species with agricultural potential, including crop wild relatives that are currently underexploited. All forage species and their crop wild relatives naturally occur on the African continent and their conservation across their native distributions is essential. Genomic and phenotypic diversity in forage clade species and their wild relatives need to be better assessed both to develop conservation strategies and to exploit the diversity in the genus for improved sustainability in Urochloa cultivar production.

Twenty years of big plant genera

In 2004, David Frodin published a landmark review of the history and concepts of big plant genera. Two decades of taxonomic activity have taken place since, coinciding with a revolution in phylogenetics and taxonomic bioinformatics. Here we use data from the World Flora Online (WFO) to provide an updated list of big (more than 500 species) and megadiverse (more than 1000 species) flowering plant genera and highlight changes since 2004. The number of big genera has increased from 57 to 86; today one of every four plant species is classified as a member of a big genus, with 14% in just 28 megadiverse genera. Most (71%) of the growth in big genera since 2000 is the result of new species description, not generic re-circumscription. More than 15% of all currently accepted flowering plant species described in the last two decades are in big genera, suggesting that groups previously considered intractable are now being actively studied taxonomically. Despite this rapid growth in big genera, they remain a significant yet understudied proportion of plant diversity. They represent a significant proportion of global plant diversity and should remain a priority not only for taxonomy but for understanding global diversity patterns and plant evolution in general.

Phylogenomics and the rise of the angiosperms

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 foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5-7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

Taxonomic resurrection of Saxifraga lancangensis (Saxifragaceae)

BACKGROUND

Accurate species delimitation is fundamental for testing evolutionary theory and provides essential implications for conservation management. The arctic-alpine genus Saxifraga L. (Saxifragaceae) is taxonomically complex and many species have not been critically assessed. The taxonomic and phylogenetic status of Saxifraga lancangensis Y.Y.Qian, considered as a synonym of Saxifraga mengtzeana Engl. & Irmsch. in previous studies, is re-evaluated in light of new evidence presented here.

RESULTS

Evidence from morphological comparison and sequencing of plastid genome indicate that S. lancangensis belongs to Saxifraga sect. Irregulares Haw., and is closely related to Saxifraga geifolia Balf.f., and S. mengtzeana. However, S. lancangensis can be diagnosed by its petals with red and clawless base, leaf blade orbicular and leaf margin shallowly dentate.

CONCLUSIONS

The morphological and molecular evidence support the resurrection of S. lancangensis as a distinct species. An updated morphological description based on protologue and fresh material, diagnostic characters, and original photographs of the resurrected species are presented.

The traditional utilization, biological activity and chemical composition of edible fern species

ETHNOPHARMACOLOGICAL RELEVANCE

Ferns form an important part of the human diet. Young fern fiddleheads are mostly consumed as vegetables, while the rhizomes are often extracted for starch. These edible ferns are also often employed in traditional medicine, where all parts of the plant are used, mostly to prepare extracts. These extracts are applied either externally as lotions and baths or internally as potions, decoctions and teas. Ailments traditionally treated with ferns include coughs, colds, fevers, pain, burns and wounds, asthma, rheumatism, diarrhoea, or skin diseases (eczema, rashes, itching, leprosy).

AIM OF THE REVIEW

This review aims to compile the worldwide knowledge on the traditional medicinal uses of edible fern species correlating to reported biological activities and isolated bioactive compounds.

MATERIALS AND METHODS

The articles and books published on edible fern species were searched through the online databases Web of Science, Pubmed and Google Scholar, with critical evaluation of the hits. The time period up to the end of 2022 was included.

RESULTS

First, the edible fern species were identified based on the literature data. A total of 90 fern species were identified that are eaten around the world and are also used in traditional medicine. Ailments treated are often associated with inflammation or bacterial infection. However, only the most common and well-known fern species, were investigated for their biological activity. The most studied species are Blechnum orientale L., Cibotium barometz (L.) J. Sm., Diplazium esculentum (Retz.) Sw., Marsilea minuta L., Osmunda japonica Thunb., Polypodium vulgare L., and Stenochlaena palustris (Burm.) Bedd. Most of the fern extracts have been studied for their antioxidant, anti-inflammatory and antimicrobial activities. Not surprisingly, antioxidant capacity has been the most studied, with results reported for 28 edible fern species. Ferns have been found to be very rich sources of flavonoids, polyphenols, polyunsaturated fatty acids, carotenoids, terpenoids and steroids and most of these compounds are remarkable free radical scavengers responsible for the outstanding antioxidant capacity of fern extracts. As far as clinical trials are concerned, extracts from only three edible fern species have been evaluated.

CONCLUSIONS

The extracts of edible fern species exert antioxidant anti-inflammatory and related biological activities, which is consistent with their traditional medicinal use in the treatment of wounds, burns, colds, coughs, skin diseases and intestinal diseases. However, studies to prove pharmacological activities are scarce, and require chemical-biological standardization. Furthermore, correct botanical classification needs to be included in publications to simplify data acquisition. Finally, more in-depth phytochemical studies, allowing the linking of traditional use to pharmacological relevance are needed to be done in a standardized way.

Toward a coordinated understanding of hydro-biogeochemical root functions in tropical forests for application in vegetation models

Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest-climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics that represent important functional processes in tropical forests. We focus on: (1) fine-root strategies for soil resource exploration, (2) coupling and trade-offs in fine-root water vs nutrient acquisition, and (3) aboveground-belowground linkages in plant resource acquisition and use. We suggest avenues for representing these extremely diverse plant communities in computationally manageable and ecologically meaningful groups in models for linked aboveground-belowground hydro-nutrient functions. Tropical forests are undergoing warming, shifting rainfall regimes, and exacerbation of soil nutrient scarcity caused by elevated atmospheric CO2. The accurate model representation of tropical forest functions is crucial for understanding the interactions of this biome with the climate.

The global distribution of angiosperm genome size is shaped by climate

Angiosperms, which inhabit diverse environments across all continents, exhibit significant variation in genome sizes, making them an excellent model system for examining hypotheses about the global distribution of genome size. These include the previously proposed large genome constraint, mutational hazard, polyploidy-mediated, and climate-mediated hypotheses. We compiled the largest genome size dataset to date, encompassing 16 017 (> 5% of known) angiosperm species, and analyzed genome size distribution using a comprehensive geographic distribution dataset for all angiosperms. We observed that angiosperms with large range sizes generally had small genomes, supporting the large genome constraint hypothesis. Climate was shown to exert a strong influence on genome size distribution along the global latitudinal gradient, while the frequency of polyploidy and the type of growth form had negligible effects. In contrast to the unimodal patterns along the global latitudinal gradient shown by plant size traits and polyploid proportions, the increase in angiosperm genome size from the equator to 40-50°N/S is probably mediated by different (mostly climatic) mechanisms than the decrease in genome sizes observed from 40 to 50°N northward. Our analysis suggests that the global distribution of genome sizes in angiosperms is mainly shaped by climatically mediated purifying selection, genetic drift, relaxed selection, and environmental filtering.

The origin and speciation of orchids

Orchids constitute one of the most spectacular radiations of flowering plants. However, their origin, spread across the globe, and hotspots of speciation remain uncertain due to the lack of an up-to-date phylogeographic analysis. We present a new Orchidaceae phylogeny based on combined high-throughput and Sanger sequencing data, covering all five subfamilies, 17/22 tribes, 40/49 subtribes, 285/736 genera, and c. 7% (1921) of the 29 524 accepted species, and use it to infer geographic range evolution, diversity, and speciation patterns by adding curated geographical distributions from the World Checklist of Vascular Plants. The orchids' most recent common ancestor is inferred to have lived in Late Cretaceous Laurasia. The modern range of Apostasioideae, which comprises two genera with 16 species from India to northern Australia, is interpreted as relictual, similar to that of numerous other groups that went extinct at higher latitudes following the global climate cooling during the Oligocene. Despite their ancient origin, modern orchid species diversity mainly originated over the last 5 Ma, with the highest speciation rates in Panama and Costa Rica. These results alter our understanding of the geographic origin of orchids, previously proposed as Australian, and pinpoint Central America as a region of recent, explosive speciation.

Extinction risk predictions for the world's flowering plants to support their conservation

More than 70% of all vascular plants lack conservation status assessments. We aimed to address this shortfall in knowledge of species extinction risk by using the World Checklist of Vascular Plants to generate the first comprehensive set of predictions for a large clade: angiosperms (flowering plants, c. 330 000 species). We used Bayesian Additive Regression Trees (BART) to predict the extinction risk of all angiosperms using predictors relating to range size, human footprint, climate, and evolutionary history and applied a novel approach to estimate uncertainty of individual species-level predictions. From our model predictions, we estimate 45.1% of angiosperm species are potentially threatened with a lower bound of 44.5% and upper bound of 45.7%. Our species-level predictions, with associated uncertainty estimates, do not replace full global, or regional Red List assessments, but can be used to prioritise predicted threatened species for full Red List assessment and fast-track predicted non-threatened species for Least Concern assessments. Our predictions and uncertainty estimates can also guide fieldwork, inform systematic conservation planning and support global plant conservation efforts and targets.

Phytochemical Profiling and Biological Activities of Rhododendron Subsect. Ledum: Discovering the Medicinal Potential of Labrador Tea Species in the Northern Hemisphere

Rhododendron subsect. Ledum is a distinct taxonomic subdivision within the genus Rhododendron, comprising a group of evergreen shrubs and small trees. This review will comprehensively analyse the phytochemical profiles and biological properties of the Rhododendron subsect. Ledum species subsect. Ledum consists of eight plant species indigenous to temperate and subarctic regions of the Northern Hemisphere, collectively known as Labrador tea. Recent investigations have concentrated on the phytochemical constituents of these plants due to limited data, emphasizing their evergreen nature and potential industrial significance. This review summarizes their major phytochemical constituents, including flavonoids, phenolic acids, and terpenoids, and discusses their potential biological activities, such as antioxidant, anti-inflammatory, antimicrobial, antitumor, hypoglycemic, hepatoprotective, neuroprotective, and cardioprotective effects. Traditional uses of these plant species align with scientific findings, emphasizing the significance of these plants in traditional medicine. However, despite promising results, gaps exist in our understanding of specific compounds' therapeutic effects, necessitating further research for comprehensive validation. This review serves as a valuable resource for researchers, identifying current knowledge, uncertainties, and emerging trends in the study of the Rhododendron subsect. Ledum species.

A new R package to parse plant species occurrence records into unique collection events efficiently reduces data redundancy

Biodiversity data aggregators, such as Global Biodiversity Information Facility (GBIF) suffer from inflation of the number of occurrence records when data from different databases are merged but not fully reconciled. The ParseGBIF workflow is designed to parse duplicate GBIF species occurrence records into unique collection events (gatherings) and to optimise the quality of the spatial data associated with them. ParseGBIF provides tools to verify and standardize species scientific names according to the World Checklist of Vascular Plants taxonomic backbone, and to parse duplicate records into unique 'collection events', in the process compiling the most informative spatial data, where more than one duplicate is available, and providing crude estimates of taxonomic and spatial data quality. When GBIF occurrence records for a medium-sized vascular plant family, the Myrtaceae, were processed by ParseGBIF, the average number of records useful for spatial analysis increased by 180%. ParseGBIF could therefore be valuable in the evaluation of species' occurrences at the national scale in support for national biodiversity plans, identification of plant areas important for biodiversity, sample bias estimation to inform future sampling efforts, and to forecast species range shifts in response to global climate change.

Inventing hyperaccumulator plants: improving practice in phytoextraction research and terminology

Toxic metals and metalloids, especially from anthropogenic sources, now pollute substantial areas of our planet. Phytoextraction is a proven technology with the potential to reduce metal/metalloid pollution, and where financially viable, recover valuable metals ('phytomining'). Toward these aims, there has been a surge of publications over the last two decades. While important progress is being made, ongoing propagation of poor practice, and the resultant drain from funding sources, is hindering this promising research area. This includes mis-ascribing hyperaccumulator species, hydroponics with extremely high dose levels, misuse of Bioconcentration Factors, use of food or biomass crops with low accumulation for phytoextraction, the phenomenon of 'template papers' in which a known hyperaccumulator for element X is dosed with element Y, or a common weed species dosed with any variety of elements to make it 'hyperaccumulate'. Here we highlight these misconceptions with the hope that this will help to: (i) disseminate accurate definitions for in planta metal accumulation; (ii) quash the propagation of poor practice by limiting the inflation of unnecessary publications via the practice of 'template paper' writing; (iii) be used by journal editors and reviewers to validate their reasoning to authors; and (iv) contribute to faster progress in delivering this technology to in-the-field practitioners.

Global patterns and ecological drivers of taxonomic and phylogenetic endemism in angiosperm genera

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation, extinction, and dispersal have influenced current distributions. Here, we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the world. We identify centers of paleo-endemism and neo-endemism of angiosperm genera, and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions, particularly in Asia and Australia. Different categories of phylogenetic endemism centers can be differentiated using current climate conditions. Current climate, historical climate change, and geographic variables together explained ∼80% of global variation in taxonomic and phylogenetic endemism, while 42-46%, 1%, and 15% were independently explained by these three types of variables, respectively. Thus our findings show that past climate change, current climate, and geography act together in shaping endemism, which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote endemism. Our study showed that many centers of phylogenetic endemism of angiosperms, including regions in Amazonia, Venezuela, and west-central tropical Africa that have not previously been identified as biodiversity hotspots, are missed by taxon-based measures of endemism, indicating the importance of including evolutionary history in biodiversity assessment.

Treemendous: an R package for integrating taxonomic information across backbones

Standardizing and translating species names from different databases is key to the successful integration of data sources in biodiversity research. There are numerous taxonomic name-resolution applications that implement increasingly powerful name-cleaning and matching approaches, allowing the user to resolve species relative to multiple backbones simultaneously. Yet there remains no principled approach for combining information across these underlying taxonomic backbones, complicating efforts to combine and merge species lists with inconsistent and conflicting taxonomic information. Here, we present Treemendous, an open-source software package for the R programming environment that integrates taxonomic relationships across four publicly available backbones to improve the name resolution of tree species. By mapping relationships across the backbones, this package can be used to resolve datasets with conflicting and inconsistent taxonomic origins, while ensuring the resulting species are accepted and consistent with a single reference backbone. The user can chain together different functionalities ranging from simple matching to a single backbone, to graph-based iterative matching using synonym-accepted relations across all backbones in the database. In addition, the package allows users to 'translate' one tree species list into another, streamlining the assimilation of new data into preexisting datasets or models. The package provides a flexible workflow depending on the use case, and can either be used as a stand-alone name-resolution package or in conjunction with existing packages as a final step in the name-resolution pipeline. The Treemendous package is fast and easy to use, allowing users to quickly merge different data sources by standardizing their species names according to the regularly updated database. By combining taxonomic information across multiple backbones, the package increases matching rates and minimizes data loss, allowing for more efficient translation of tree species datasets to aid research into forest biodiversity and tree ecology.

Atlas Florae Europaeae notes, 35. Further critical notes on Cytisussect.Tubocytisus (Fabaceae) in Europe

A few species names in Cytisussect.Tubocytisus are re-assessed and taxonomically evaluated. Diagnostic characters are discussed and the species status of C.absinthioides Janka, C.eriocarpus Boiss., C.frivaldszkyanus Degen, C.jankae Velen. and C.smyrnaeus Boiss. is confirmed. The holotype of Cytisustriflorus Lam. was found to belong to C.hirsutus L. rather than to the C.ratisbonensis group as currently treated. Cytisuslasiosemius Boiss. is not the correct name for C.frivaldszkyanus Degen, but another synonym of C.hirsutus. Cytisuslitwinowii V.I.Krecz., which was known solely from the holotype, is a synonym of C.austriacus L. s.str. Chamaecytisuspseudojankae Pifkó & Barina, reported from a small area shared between Albania, Greece and North Macedonia, is treated as a subalpine variant of C.austriacus. Cytisustmoleus Boiss. is removed from the synonymy of C.eriocarpus and added to the synonymy of C.pygmaeus Willd. Cytisusfalcatussubsp.albanicus Degen & Dörfl. and C.pubescens Gilib. are synonymised with C.hirsutus. Cytisusmicrophyllus Boiss. is moved from C.austriacus s.l. to the synonymy of C.frivaldszkyanus, and C.pindicola (Degen) Halácsy to the synonymy of C.jankae. Chamaecytisuscalcareus (Velen.) Kuzmanov is accepted as Cytisuscalcareus (Velen.) Sennikov & Val.N.Tikhom., comb. nov., and its distribution is circumscribed. Cytisushirsutusvar.ciliatus (Wahlenb.) Hazsl. and C.polytrichusvar.subglabratus Val.N.Tikhom. & Sennikov, var. nov. are recognised as glabrous variants of the corresponding species. Lectotypes of C.ciliatus, C.hirsutissimus K.Koch, C.jankae, C.lasiosemius, C.pubescens, C.rhodopeus J.Wagner ex Bornm. and C.thirkeanus K.Koch are designated. Cytisuspolytrichus is reported from the Western Caucasus in place of C.wulffii auct.

Plant invasion and naturalization are influenced by genome size, ecology and economic use globally

Human factors and plant characteristics are important drivers of plant invasions, which threaten ecosystem integrity, biodiversity and human well-being. However, while previous studies often examined a limited number of factors or focused on a specific invasion stage (e.g., naturalization) for specific regions, a multi-factor and multi-stage analysis at the global scale is lacking. Here, we employ a multi-level framework to investigate the interplay between plant characteristics (genome size, Grime's adaptive CSR-strategies and native range size) and economic use and how these factors collectively affect plant naturalization and invasion success worldwide. While our findings derived from structural equation models highlight the substantial contribution of human assistance in both the naturalization and spread of invasive plants, we also uncovered the pivotal role of species' adaptive strategies among the factors studied, and the significantly varying influence of these factors across invasion stages. We further revealed that the effects of genome size on plant invasions were partially mediated by species adaptive strategies and native range size. Our study provides insights into the complex and dynamic process of plant invasions and identifies its key drivers worldwide.

Characterization and phylogenetic analysis of the complete plastid genome of Theobroma bicolor (Malvaceae) from Peru

Theobroma bicolor Bonpl. 1806 is distributed in the Neotropics from southern Mexico to the Peruvian and Brazilian Amazon. High-throughput sequencing of T. bicolor from Peru (KUELAP2926) resulted in the assembly of its complete plastid genome (GenBank accession number OQ557154). The chloroplast genome of T. bicolor is A + T-rich (62.97%), having 160,317 bp in size and containing 130 genes; including a pair of inverted repeat regions (IRs) of 25,462 bp separated by a large single copy region (LSC) of 89,221 bp and a small single copy region (SSC) of 20,172 bp. This plastid genome is similar in length, content, and organization to other members of the genus Theobroma. Phylogenetic analyses of T. bicolor support its sistership to the clade comprising T. cacao and T. grandiflorum. This study may contribute valuable information to the phylogenetic relationships within the genus Theobroma.

Comprehensive safety assessment of serendipity berry sweet protein produced from Komagataella phaffii

Serendipity berry plant (Dioscoreophyllum cumminsii (Stapf) Diels) is the source of a naturally sweet protein referred to as monellin. The safety of serendipity berry sweet protein (SBSP) containing single polypeptide monellin (MON) expressed in Komagataella phaffii (formerly Pichia pastoris) and produced via precision fermentation was examined comprehensively through assessments of in vitro and in silico protein digestion, in silico allergenicity, in vitro genotoxicity (reverse mutation and mammalian micronucleus assays), and 14-day and 90-day oral (dietary) toxicity studies in rats. There was no indication of allergenicity for SBSP in the in silico analyses. Results from both in vitro and in silico protein digestibility assessments indicated that SBSP is digested upon ingestion and would therefore be unlikely to pose a toxigenic or allergenic risk to consumers. SBSP was non-genotoxic in in vitro assays and showed no adverse effects in the 14-day or 90-day toxicity studies up to the highest dose tested. The 90-day toxicity study supports a NOAEL for SBSP of 1954 mg/kg bw/day, which corresponds to a NOAEL for MON of 408 mg/kg bw/day.

A mixed-apoptotic effect of Jurinea mesopotamica extract on prostate cancer cells: a promising source for natural chemotherapeutics

This research investigates the potential use of Jurinea mesopotamica Hand.-Mazz. (Asteraceae) in cancer treatment. In this study, a plant extract was prepared using all parts of J. mesopotamica, and its effect on the proliferation of cancer and normal cells was tested using the MTT method. It was found to have a selective cytotoxic effect on prostate cancer cells, with the lowest IC50 (half-maximal inhibitory concentration) of 10μg/mL found in the butanol extract (JMBE). The extract suppressed the proliferation of prostate cancer cells (67 %), disrupted organelle integrity (49 %), increased reactive oxidative stress (66 %), and triggered cell death (51 %). In addition, apoptotic gene expressions and protein levels increased, and the profile of amino acids related to energy metabolism was elevated. Based on LC-MS/MS results, the plant contained higher levels of flavonoids, including isoquercitrin, cosmosiin, astragalin, nicotiflorin, luteolin, and apigenin. These results suggest that J. mesopotamica has a selective effect on prostate cancer due to its high flavonoid content and might be a promising natural alternative for cancer treatment.

Phytochemicals from Pterocarpus angolensis DC and Their Cytotoxic Activities against Breast Cancer Cells

Pterocarpus anglonesis DC is an indigenous medicinal plant belonging to the Pterocarpus genus of the Fabaceae family. It is used to treat stomach problems, headaches, mouth ulcers, malaria, blackwater fever, gonorrhea, ringworm, diarrhea, heavy menstruation, and breast milk stimulation. Column chromatography of the stem bark extracts resulted in the isolation of eight compounds, which included friedelan-3-one (1), 3α-hydroxyfriedel-2-one (2), 3-hydroxyfriedel-3-en-2-one (3), lup-20(29)-en-3-ol (4), Stigmasta-5-22-dien-3-ol (5), 4-O-methylangolensis (6), (3β)-3-acetoxyolean-12-en-28-oic acid (7), and tetradecyl (E)-ferulate (8). The structures were established based on NMR, IR, and MS spectroscopic analyses. Triple-negative breast cancer (HCC70), hormone receptor-positive breast cancer (MCF-7), and non-cancerous mammary epithelial cell lines (MCF-12A) were used to test the compounds' cytotoxicity. Overall, the compounds showed either no toxicity or very low toxicity to all three cell lines tested, except for the moderate toxicity displayed by lupeol (4) towards the non-cancerous MCF-12A cells, with an IC50 value of 36.60 μM. Compound (3β)-3-acetoxyolean-12-en-28-oic acid (7) was more toxic towards hormone-responsive (MCF-7) breast cancer cells than either triple-negative breast cancer (HCC70) or non-cancerous breast epithelial (MCF-12A) cells (IC50 values of 83.06 vs. 146.80 and 143.00 μM, respectively).

The global distribution of plants used by humans

Plants sustain human life. Understanding geographic patterns of the diversity of species used by people is thus essential for the sustainable management of plant resources. Here, we investigate the global distribution of 35,687 utilized plant species spanning 10 use categories (e.g., food, medicine, material). Our findings indicate general concordance between utilized and total plant diversity, supporting the potential for simultaneously conserving species diversity and its contributions to people. Although Indigenous lands across Mesoamerica, the Horn of Africa, and Southern Asia harbor a disproportionate diversity of utilized plants, the incidence of protected areas is negatively correlated with utilized species richness. Finding mechanisms to preserve areas containing concentrations of utilized plants and traditional knowledge must become a priority for the implementation of the Kunming-Montreal Global Biodiversity Framework.

Current status of global conservation and characterisation of wild and cultivated Brassicaceae genetic resources

BACKGROUND

The economic importance of the globally distributed Brassicaceae family resides in the large diversity of crops within the family and the substantial variety of agronomic and functional traits they possess. We reviewed the current classifications of crop wild relatives (CWRs) in the Brassicaceae family with the aim of identifying new potential cross-compatible species from a total of 1,242 species using phylogenetic approaches.

RESULTS

In general, cross-compatibility data between wild species and crops, as well as phenotype and genotype characterisation data, were available for major crops but very limited for minor crops, restricting the identification of new potential CWRs. Around 70% of wild Brassicaceae did not have genetic sequence data available in public repositories, and only 40% had chromosome counts published. Using phylogenetic distances, we propose 103 new potential CWRs for this family, which we recommend as priorities for cross-compatibility tests with crops and for phenotypic characterisation, including 71 newly identified CWRs for 10 minor crops. From the total species used in this study, more than half had no records of being in ex situ conservation, and 80% were not assessed for their conservation status or were data deficient (IUCN Red List Assessments).

CONCLUSIONS

Great efforts are needed on ex situ conservation to have accessible material for characterising and evaluating the species for future breeding programmes. We identified the Mediterranean region as one key conservation area for wild Brassicaceae species, with great numbers of endemic and threatened species. Conservation assessments are urgently needed to evaluate most of these wild Brassicaceae.

The dynamic changes in pigment metabolites provide a new understanding of the colouration of Pyracantha fortuneana at maturity

The type, content and accumulation characteristics of pigments are the material basis for fruit colour and the evaluation basis of the fruit maturity and nutritional value of P. fortuneana. However, little information is available on the changes in carotenoids, anthocyanins, procyanidins and major flavones during the ripening process of P. fortuneana fruits. Thus, this study investigated the colour conversion characteristics, the main changes in the above four metabolites and the association landscape with those metabolites. The results showed that thirty-nine kinds of carotenoids and derivatives, eighteen anthocyanins, five procyanidins and five flavone compounds were identified in the fruits of P. fortuneana. The total content and contents of most individual carotenoids, anthocyanins, procyanidins and flavones reached the highest values at the TS2, TS4, TS1 and TS1 stages, respectively. Among the variations, the contents of β-carotene and lutein increased first and then decreased, cyanidin-3-galactoside and cyanidin-3-glucoside accumulated, the concentrations of procyanidin C1 and procyanidin B2 decreased, and the contents of rutin and quercetin-3-O-glucoside also decreased; these changers were responsible for the main changes in carotenoids, anthocyanidin, procyanidins and flavones, respectively. For the correlation analysis results, there might be two modes of action that together affected the colour conversion of P. fortuneana fruits during ripening, i.e., (E/Z)-phytoene communicated with the carotenoid metabolic pathway that might promote the accumulated ABA content, which might cause the increased anthocyanidin (primarily through cyanidin-3-(6-malonyl-beta-d-glucoside) (C3MG)) at the final stage; most of the decreased flavone and procyanidin metabolites produced by the flavonoid metabolic pathway were another important factor affecting the accumulation of C3MG.

Molecular phylogeny of Vincetoxicum (Apocynaceae, Asclepiadoideae) from Thailand and integrative taxonomy corroborating a new cryptic species within Vincetoxicum kerrii

An updated phylogeny of the genus Vincetoxicum s.l. based on DNA sequences of the nuclear internal transcribed spacer (ITS) region and three plastid markers is presented. In total, 21 accessions newly sequenced from Thailand were added to the dataset of the homologous sequences of 75 other Vincetoxicum taxa downloaded from GenBank. In our analysis, the relationships between the well-supported clades largely correspond to those revealed in previous studies. With some exceptions, the phylogenetic positions of the Thai taxa in relation to other conspecifics and congeners generally reflect the geographic distributions of taxa. Moreover, recent extensive sampling throughout Thailand and in-depth investigation have revealed V. kerrii, a slender twiner widespread from South China to Indo-China, to be a species complex. A combination of molecular, morphological, anatomical, ultrastructural and ecological evidence allowed us to reveal a new cryptic species hidden within V. kerrii, described here under the name V. simplex. A comprehensive description, illustrations, photographs, and comparison with the morphologically similar species are provided. Although V. simplex and V. kerrii s.s. resemble one another in various aspects of vegetative and reproductive structures, the latter is phylogenetically closely related to V. irrawadense, which is much less similar morphologically to both V. simplex and V. kerrii s.s. than the latter two are to each other. In addition to the new cryptic species recognized in the present study, a new record for Thailand, V. microstachys, is also reported.

Antitumor and Phytochemical Properties of Ferula assa-foetida L. Oleo-Gum-Resin against HT-29 Colorectal Cancer Cells In Vitro and in a Xenograft Mouse Model

Colorectal cancer (CRC) is one of the most frequently occurring tumors. Ferula assa-foetida oleo-gum-resin (OGR) extract is a traditional cooking spice known for its broad spectrum of biological activities such as antifungal, antiparasitic, and anti-inflammatory activities. This study evaluated the antitumor effect of OGR extract against HT-29 colorectal cancer cells. The OGR chemical composition was analyzed using LC-ESI-MS/MS; MTT, clonogenic assays, and a xenograft model were used to measure cytotoxicity, while apoptotic proteins were detected using Western blotting. Phytochemical analysis revealed that the extract was a rich source of isoflavones, xanthones, and other derivatives. In a dose-dependent manner, the OGR extract significantly inhibited colony formation ability and HT-29 cell growth (IC50 was 3.60 ± 0.02 and 10.5 ± 0.1 mg/mL, respectively). On the other hand, the OGR extract significantly induced apoptosis and increased the expression of some pro-death proteins involved in cellular apoptosis including PUMA, BIM, BIK, and BAK. Moreover, in a subcutaneous HT-29 xenograft model, the tumor volume and burden decreased after treatment with the OGR extract (550 ± 32 mm3 and 16.3 ± 3.6, respectively) This study demonstrated that Ferula assa-foetida OGR ethanolic extract has potential antitumor effects against HT-29 CRC cell lines by reducing cell viability and the function of apoptosis. More studies are needed to reveal the underlying mechanisms related to cytotoxicity and apoptosis induction.

Phytochemical Analysis of Anacamptis coriophora Plant Cultivated Using Ex Vitro Symbiotic Propagation

This study aims to investigate the functional groups and phytochemical profile of Anacamptis coriophora seeds, tubers, and flowers. Symbiotic seedlings produced using the ex vitro method were transferred to their natural habitat and grown to analyze the functional groups and phytochemical profiles of tubers and flowers. The life cycles of the transferred seedlings were monitored, and tubers and flowers were harvested for analysis. ATR-FTIR spectroscopy revealed the presence of functional groups such as polysaccharides, lignin, and proteins in both tubers and flowers. Differences in spectral frequencies between first-year and second-year tubers were observed. Fatty acid analysis identified 30 different compounds in seeds, flowers, and tubers, with linoleic acid being the most abundant (27 % in seeds, 33 % in tubers), and palmitic acid present in flowers (24 %). GC-MS analysis of ethanol extracts from these components highlighted the presence of 32 compounds, including hydroxyacetic acid, hydrazide, cytidine (Z)-7-hexadecenal, 2,2-dimethoxyethane, 2,5,6-trimethyldecane, and butanamide, 4-amino-N-hydroxy. A. coriophora's tubers, flowers, and seeds may contain active metabolites with therapeutic potential. These results are valuable for the commercial cultivation of the plant.

A comprehensive review on the ethnobotanical, phytochemical, and pharmacological aspects of the genus Malvastrum

The genus Malvastrum, from the family Malvaceae, is a small genus of twenty four species, distributed worldwide. Some of the species have a long and rich history of ethnobotanical and traditional medicinal uses. Few reports of systematic scientific studies can be found in the literature which highlight the rich chemical profile and pharmacological properties of the genus. This is the first ever attempt to compile the available literature and provide a critical overview for future studies on the genus. For this purpose, several databases, such as PubMed, Scifinder, Elsevier, Google Scholar, and others were utilized. Literature records the presence of bioactive metabolites in the genus, effective against dysentery, gastrointestinal distress, fever, enteritis, hepatitis, cough, sore throat, arthritis, and diabetes. Seventy four biologically active secondary metabolites have been identified from different species of Malvastrum, including four pure isolates. Furthermore, this report also documents their potential properties. This article may prove as a milestone for new researchers, eager to work on Malvastrum species and perform further in-depth studies on this genus.

Angiosperm phylogenetic diversity is lower in Africa than South America

Although originating from a common Gondwanan flora, the diversity and composition of the floras of Africa and South America have greatly diverged since continental breakup of Africa from South America now having much higher plant species richness. However, the phylogenetic diversity of the floras and what this tells us about their evolution remained unexplored. We show that for a given species richness and considering land surface area, topography, and present-day climate, angiosperm phylogenetic diversity in South America is higher than in Africa. This relationship holds regardless of whether all climatically matched areas or only matched areas in tropical climates are considered. Phylogenetic diversity is high relative to species richness in refugial areas in Africa and in northwestern South America, once the gateway for immigration from the north. While species richness is strongly influenced by massive plant radiations in South America, we detect a pervasive influence of historical processes on the phylogenetic diversity of both the South American and African floras.

Three in four undescribed plant species are threatened with extinction

This article is part of the Special Collection ‘Global plant diversity and distribution’. See https://www.newphytologist.org/global-plant-diversity for more details.

Reconciling fossils with phylogenies reveals the origin and macroevolutionary processes explaining the global cycad biodiversity

The determinants of biodiversity patterns can be understood using macroevolutionary analyses. The integration of fossils into phylogenies offers a deeper understanding of processes underlying biodiversity patterns in deep time. Cycadales are considered a relict of a once more diverse and globally distributed group but are restricted to low latitudes today. We still know little about their origin and geographic range evolution. Combining molecular data for extant species and leaf morphological data for extant and fossil species, we study the origin of cycad global biodiversity patterns through Bayesian total-evidence dating analyses. We assess the ancestral geographic origin and trace the historical biogeography of cycads with a time-stratified process-based model. Cycads originated in the Carboniferous on the Laurasian landmass and expanded in Gondwana in the Jurassic. Through now-vanished continental connections, Antarctica and Greenland were crucial biogeographic crossroads for cycad biogeography. Vicariance is an essential speciation mode in the deep and recent past. Their latitudinal span increased in the Jurassic and restrained toward subtropical latitudes in the Neogene in line with biogeographic inferences of high-latitude extirpations. We show the benefits of integrating fossils into phylogenies to estimate ancestral areas of origin and to study evolutionary processes explaining the global distribution of present-day relict groups.

Africa as an evolutionary arena for large fruits

Strong paleoclimatic change and few Late Quaternary megafauna extinctions make mainland Africa unique among continents. Here, we hypothesize that, compared with elsewhere, these conditions created the ecological opportunity for the macroevolution and geographic distribution of large fruits. We assembled global phylogenetic, distribution and fruit size data for palms (Arecaceae), a pantropical, vertebrate-dispersed family with > 2600 species, and integrated these with data on extinction-driven body size reduction in mammalian frugivore assemblages since the Late Quaternary. We applied evolutionary trait, linear and null models to identify the selective pressures that have shaped fruit sizes. We show that African palm lineages have evolved towards larger fruit sizes and exhibited faster trait evolutionary rates than lineages elsewhere. Furthermore, the global distribution of the largest palm fruits across species assemblages was explained by occurrence in Africa, especially under low canopies, and extant megafauna, but not by mammalian downsizing. These patterns strongly deviated from expectations under a null model of stochastic (Brownian motion) evolution. Our results suggest that Africa provided a distinct evolutionary arena for palm fruit size evolution. We argue that megafaunal abundance and the expansion of savanna habitat since the Miocene provided selective advantages for the persistence of African plants with large fruits.

Global hotspots of plant phylogenetic diversity

Regions harbouring high unique phylogenetic diversity (PD) are priority targets for conservation. Here, we analyse the global distribution of plant PD, which remains poorly understood despite plants being the foundation of most terrestrial habitats and key to human livelihoods. Capitalising on a recently completed, comprehensive global checklist of vascular plants, we identify hotspots of unique plant PD and test three hypotheses: (1) PD is more evenly distributed than species diversity; (2) areas of highest PD (often called 'hotspots') do not maximise cumulative PD; and (3) many biomes are needed to maximise cumulative PD. Our results support all three hypotheses: more than twice as many regions are required to cover 50% of global plant PD compared to 50% of species; regions that maximise cumulative PD substantially differ from the regions with outstanding individual PD; and while (sub-)tropical moist forest regions dominate across PD hotspots, other forest types and open biomes are also essential. Safeguarding PD in the Anthropocene (including the protection of some comparatively species-poor areas) is a global, increasingly recognised responsibility. Having highlighted countries with outstanding unique plant PD, further analyses are now required to fully understand the global distribution of plant PD and associated conservation imperatives across spatial scales.

A global assessment of the Raunkiaeran shortfall in plants: geographic biases in our knowledge of plant traits

This article is part of the Special Collection ‘Global plant diversity and distribution’. See https://www.newphytologist.org/global-plant-diversity for more details.

Re-evaluating the importance of threatened species in maintaining global phytoregions

Anthropogenic introductions are known to be changing the structure of global phytogeographical regions (phytoregions), but previous studies have been limited by incomplete or biased data sets that are likely to underestimate the importance of threatened species. In this work, we analyse a comprehensive data set of all known species and their occurrences (at botanical country resolution) to quantify the impact of potential future extinction scenarios. We used Infomap, a network-based community detection algorithm, to generate phytoregional delineations for six species-distribution scenarios (native, introduced and extinctions of species that are either documented as threatened or likely to be threatened, as well as combinations thereof). We compared the numbers and sizes of phytoregions to characterise the amount and spatial distribution of changes in global phytoregions under each scenario. Extinctions of species that are predicted to be threatened had a greater homogenising effect on phytoregions than introductions, and there was some evidence that introductions may even mitigate the homogenisation caused by extinctions, though this interaction is complex. This research provides the first evidence that the loss of threatened species would have significant ramifications for global phytoregions and demonstrates the need to consider extinction processes in studies of anthropogenic effects on biodiversity patterns.