PLANTS, PEOPLE, PLANET

O_LIDutch elm disease has devastated the treescapes of Europe and North America, causing large elm trees to become largely absent in many areas. Several decades of work are now coming to fruition with the availability of potentially resistant cultivars for restoration. C_LIO_LIHere, using single nucleotide polymorphisms (SNPs) derived from whole genome sequences of over 200 trees, we investigate the genomic diversity of elm trees growing historically in Britain and Europe, and that of some new cultivars; including widespread native European and British elms; exotic elm species with natural resistance; and the often-complex hybrids between these and native elms available from the various breeding programmes and living collections. We also sequenced a variety of disease-resistant selections from Spain of interest for planting in Britain. C_LIO_LIWhile confirming many specimen labels and multi-generational crossing records, our results also revealed unexpected misidentifications and origins of some samples. This included past hybridisation in some resistant selections thought to be pure species. We find that within our samples, field elm (Ulmus minor) is more genetically diverse C_LIO_LIthan Wych elm (U. glabra). We show that over ten British elm morphological forms sometimes assigned species epithets fall within the genetic range of U. minor. C_LIO_LIWith their often-exotic parentage, many of the elm cultivars introduced into Britain post-epidemic inevitably represent a considerable increase in nucleotide diversity over the still numerically large, native U. minor and U. glabra populations. Currently, the cultivars are being planted mainly as ornamentals. Their long term arboricultural, adaptive and landscape suitability compared to native elms remains to be demonstrated. C_LI

Climatic and biogeographic variables are often used as a proxy for tree genetic diversity, but local factors can also influence it. We propose that woodland age, presence of ancient trees, and population size could impact genetic diversity. Using the RBG Kew UK National Tree Seed Project as a study case, we examined how these factors are accounted for during seed collection. We found 42% of tree seed collections come from ancient woodlands and that 8.4% overlap with ancient trees. Sampled forest patches size ranges from few individuals to several thousand. We then carried out a pilot to examine the role of population size on functional traits variation, testing the relationship between population size and seed germination and seedling thermal stress sensitivity in three populations of the Betula pubescens Ehrh. complex. We found that seeds and seedlings from larger populations showed higher fitness and stress resistance. Our results highlight the importance of local factors to predict variation in functional traits, relevant for tree resilience. Existing seed collections of native species stored in conservation seed banks offer a valuable resource to explore these factors and improve our understanding of genetic diversity in tree populations, with implications for biodiversity conservation and forestry production.

(1) BackgroundSaffron crocus (Crocus sativus) is the source of saffron, the most expensive spice in the world. It evolved about 3000 years ago as a sterile triploid clone in Greece. Since then, saffron has spread across the globe, where regionally distinct practices of saffron cultivation have developed. Despite differences in morpho-physiological traits, genetic variability is low, if present at all. Here, we aim to resolve chromosomal and sequence-associated variability across saffron crocus cultivars from the crops main cultivation areas in Africa, Asia and Europe. (2) MethodsWe used genome-wide DNA polymorphisms obtained through genotyping-by-sequencing (GBS) of 33 saffron and 14 closely related Crocus accessions, which we place into a phylogenetic context. For karyotyping, we compare nine saffron accessions by multi-color fluorescent in situ hybridisation (FISH) with repetitive DNA probes. (3) Key resultsPhylogenetic analyses confirmed the single origin and clonal nature of all saffron accessions. We detected slight DNA differences among saffron crocus genotypes, which were minor compared with those in wild C. cartwrightianus populations. Still, the Iranian saffron accessions form a genetically very narrow group that differs from the other proveniences in population genetic analyses. However, chromosomes of some saffron accessions display variable FISH signals, likely resulting from gains and losses of tandemly repeated DNA. (4) Main conclusionsBased on the high genetic identity and small karyotypic differences, we confirm the clonal origin of the saffron accessions. Nevertheless, as we detected small and regional chromosomal variability, we conclude that at least four somaclonal saffron lineages emerged after saffrons origin. Societal Impact StatementFor millennia, many cultures developed cultivation practices and regional crop varieties. A notable case is saffron, the worlds most expensive spice that is harvested from stigmas of saffron crocus. This flower crop arose 3000 years ago in a singular genome triplication event and since then spread clonally across the globe. By identifying genetic and chromosomal variability in clonal saffron accessions, we highlight regional diversity, support the preservation of traditional knowledge, and underscore the risk of relying on only one clonal lineage. This informs strategies for saffron cultivation, linking cultural heritage with modern genomics to address biodiversity, evolution, and food security.

Understanding crop genetic diversity is essential for conservation and breeding, yet farmer-maintained germplasm remains largely underrepresented in genomic studies. Theobroma cacao L. has a complex domestication history and extensive global diversity, and cacao currently cultivated in Central America, particularly in Costa Rica, has been understudied compared to South American and Mexican cultivars despite cultural and historical importance. In this study, we investigate the genetic diversity of cacao from farmer-managed systems across Costa Rica to search for Criollo germplasm and identify and characterize any unique local genetic groups. Ninety-four trees were sampled from 17 farms across four regions of the country and sequenced using whole genome resequencing. Farmer materials were analyzed alongside 166 previously characterized reference accessions representing major cacao genetic groups. Population structure analyses, phylogenetic reconstruction, and network approaches revealed that Costa Rican cacao encompasses multiple known genetic groups, including Criollo-derived lineages, while also harboring locally distinct diversity not fully represented in current global reference collections. Analyses revealed close kinship between many accessions with no clear geographic patterns corresponding to the observed population differentiation, reflecting the effects of farmers in creating dominant patterns of gene flow through seed-saving, clonal propagation, and sharing genotypes among farms. Heterozygosity levels varied substantially among individuals, consistent with a mixture of highly inbred Criollo trees and more heterozygous, admixed genotypes. We find that farmer-managed cacao systems are reservoirs of genetic diversity, including possibly rare or historically important lineages, underscoring the value of these farming systems for effective conservation and management of genomic resources for cacao resilience and improvement.

PremiseHerbarium specimens are increasingly used to extract morphological traits for ecological and evolutionary studies, yet the effects of tissue desiccation on trait measurements remain poorly understood. Here, we tested whether higher tissue water content leads to greater measurement changes after herborization (H1) and whether fresh trait values can be reliably predicted from herbarium measurements (H2). MethodsWe evaluated the reliability of herbarium-based measurements by comparing fresh and dried traits of leaves, flowers, fleshy fruits, and seeds across 262 individuals representing 133 Neotropical Myrtaceae species. Phylogenetic least square models and machine-learning regressions were used to test H1 and H2. ResultsLeaves and flowers generally shrank after herborization, fruits size metrics tended to increase, and seeds were largely unaffected. Water content was significantly associated with the magnitude of herborization effects in flowers and some leaf and seed traits. Fresh trait values were accurately predicted from herbarium measurements. Prediction errors were lowest for leaf traits, followed by fruits, flowers, and seeds. DiscussionThese results partially support H1 and support H2, indicating that herbarium specimens can be reliably used for trait analyses when organ-specific responses are considered, providing a practical framework to account for potential desiccation bias in functional trait research.

Belemia belongs to Nyctaginaceae and comprises two species of delicate vines. Both species are endemic to Brazil. Belemia fucsioides, the type species, described in 1981, occurs in a restricted area of the Atlantic Forest in southeastern Brazil. Belemia cordata, described in 2020, is known from only two records from the same area in the Cerrado of northern Brazil. Here, we describe the taxonomic history of Belemia and provide the first synopsis for the genus. We include species description, distribution map, identification key, and anatomical data. We used field observations over the past decade and modeled anthropogenic changes in the species range to conduct a conservation assessment in accordance with the IUCN Red List criteria. Conservation assessments indicate significant concerns for Belemia, classified as either endangered (B. fucsioides) or critically endangered (B. cordata). The species are threatened primarily by habitat loss to land used for agriculture, forestry, and livestock production. This study contributes to ongoing initiatives exploring plant diversity in the Neotropics and supports efforts to identify threats to biodiversity.

Background and aimsThis study combines morphological and environmental data to better understand a Brunfelsia (Solanaceae) species complex, aiming to clarify patterns of variation and identify ecological factors that shape morphotype boundaries. Such an approach provides a broader perspective on how organisms respond to environmental gradients and contributes to a more comprehensive understanding of biodiversity. MethodsWe analyzed 273 herbarium specimens for 13 morphological traits using univariate and ordination analyses, namely PCA and CVA. Climatic and edaphic variables were extracted for 147 specimens with georeferenced records. To assess habitat suitability and the ecological niche of each predefined morphotype, niche models under present conditions and niche overlap tests were conducted. A redundancy analysis (RDA) was applied to evaluate how environmental predictors explain variation in vegetative and floral traits. Finally, DAPC was used to estimate membership probabilities based on morphological and environmental data. Key ResultsTwo well-differentiated groups were recovered: the capitata-hydrangeiformis morphotype, allegedly composing a cline, and the ecologically and morphologically distinct "bahia" morphotype. Variation in floral traits was better explained by environmental predictors than variation in vegetative traits; moreover, floral traits were able to delineate morphotypes more robustly when plotted in isolation. However, when analyzing the results of ecological niche overlap, a significant ecological separation of the "bahia" morphotype from the others was observed. Therefore, key morphological characters for the taxonomy of Brunfelsia covary in part with environmental variables. ConclusionsThese findings support the recognition of "bahia" morphotype as a distinct species to be formally described. This integrative approach contributes to understanding diversification processes in biodiversity hotspots and highlights hidden taxonomic diversity within Brunfelsia, where many rare and narrow-endemic taxa lie.

(1) RationaleQuantifying and predicting plant morphology is central to understanding development and evolution, yet many plant forms lack homologous features required for traditional morphometrics. We apply the Euler Characteristic Transform (ECT), an injective descriptor from topological data analysis, to encode 2D plant shapes. The ECT converts contours into image-like representations that preserve shape information while enabling deep learning. (2) MethodsWe computed ECTs for large datasets of leaf and pavement cell shapes and used convolutional neural networks (CNNs) for classification. We also trained CNNs to approximate the inverse mapping, predicting leaf shape masks from radial ECTs. (3) Key resultsECT-based models achieved high classification accuracy, surpassing previous approaches on millions of herbarium-derived leaves. Notably, grapevine leaf venation was predicted from blade geometry alone, demonstrating that vascular structure is encoded in the outline. (4) Main conclusionThe ECT provides a compact, information-preserving representation of biological shape that integrates naturally with deep learning. It enables both accurate classification and predictive reconstruction, revealing latent morphological information and offering new opportunities to study plant form across scales.

Forest regeneration depends not only on how many seeds trees produce, but on the physiological quality of those seeds. Yet while climate-driven shifts in seed quantity and masting have received sustained attention, the parallel question of whether climate change degrades seed quality remains poorly resolved. Using a nationwide dataset of seed mass and viability in European beech (Fagus sylvatica L.) collected between 1996 and 2024 (13,349 seed lots from 381 forest districts across Poland), with climate-quality analyses focused on 5,374 freshly harvested seed lots from 353 districts (2004-2023), we asked whether the two components of seed quality respond to different seasonal climatic windows, and whether harvest-year climate also shapes seed performance during long-term cold storage. Seed mass and seed viability were only weakly correlated (Spearmans {rho} = 0.15), acting as two independent dimensions of seed quality. Both revealed substantial temporal variation over the study period, but along distinct trajectories. Seed mass declined markedly between segmented-regression breakpoints in 2009 and 2019, more steeply at higher latitudes, coinciding spatially and temporally with the masting breakdown reported at the species northeastern range margin. Climatic associations were correspondingly divergent. Viability was positively associated with previous summer temperature, consistent with temperature-cued flower initiation, and negatively with spring temperature in the harvest year, plausibly reflecting thermal disruption of early embryogenesis. Seed mass showed no significant association with any seasonal climatic predictor, indicating control by slower or unmeasured processes. Storage duration progressively reduced viability, and this decline was further modulated by climate during seed development, with seeds developing under climatically suboptimal conditions losing viability faster. These results expose a hidden decoupling between seed quantity and seed quality under contemporary climate change, with direct consequences for forest regeneration and for ex situ conservation strategies that assume mast-year seeds will remain viable for decades.

If youve ever complained about a species name thats a mouthful--say, the soldier fly Parastratiosphecomyia stratiosphecomyioides or the myxobacterium Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis--youre in very good company. But could the readability of binomial scientific names cause more than complaints? Could it influence how much species are studied and talked about? We examined a random sample of 3,019 species names spanning 29 phyla/divisions. We tested whether name length and reading difficulty are associated with species representation in the scientific literature (measured via literature mentions) and their visibility to the public (measured via Wikipedia pageviews). Both species name traits showed significant negative relationships with literature mentions and Wikipedia reads. Increasing name length from 10 to 30 characters is associated with a 66% decrease in expected mentions and a 65% decrease in Wikipedia reads, while shifting from the most to the least readable name in the dataset corresponds to 53% and 76% decreases. These patterns are consistent with something familiar: the fickleness of human attention, responding to features of the world that are far from rational. While creativity in naming is a cherished part of taxonomy, a touch of orthographic restraint may ultimately benefit both science and the species themselves--especially among understudied uncharismatic taxa.

Lucerne is gaining interest as a living mulch in agroecological productions. However, its vigorous growth can lead to competition with cash crops for light and nutrients, necessitating new ideotypes. This study investigated the genetic basis of traits relevant to ideotype breeding: dormancy, spring regrowth, height, growth habit, leaflet size, stem diameter, and plant structure. Individuals from a diversity panel of 27 accessions and a synthetic population were phenotyped in a spaced plant nursery. Over 100,000 SNP markers were used for genotyping. Genome-wide association study (GWAS) and genomic prediction were conducted, considering population structure. Heritability estimates ranged from moderate to high in diversity panel (h{superscript 2} = 0.36-0.70) but were lower in synthetic population (h{superscript 2} = 0.17-0.33), reflecting reduced genetic variance. Trait correlations differed markedly between populations, indicating the possibility of recombining traits to create new ideotypes. GWAS identified a few QTL (r{superscript 2} up to 0.27) for leaflet size, height, growth habit, and plant structure, with candidate genes linked to growth, stress response, and signalling pathways. Genomic prediction was highly accurate in diversity panel, where broad genetic variation allowed reliable estimation of marker effects, with prediction accuracies exceeding 0.8 for heritable traits, including growth habit and leaflet size. In contrast, accuracies were low in synthetic population, reflecting its limited diversity and small size, whether training was based on the synthetic population itself or on the diversity panel. These results highlight the potential to recombine traits and develop lucerne ideotypes using molecular tools such as QTL detection and genomic prediction.

Banana (Musa spp.) is a vital staple food and cash crop cultivated in over 140 countries, providing nourishment and livelihoods to more than 400 million people worldwide. In this context, Bhimkol (Musa balbisiana, BB genome), a diploid banana variety native to Northeast India holds significant nutritional and commercial value. Its high iron and nutrient content have already been commercially validated through products like Bhimvita and Bhimshakti, which utilize fresh fruit pulp as nutrient-rich food for infants. However, Bhimkol fruits typically contain 100-150 seeds, an undesirable trait for product development. The manual removal of these seeds significantly increases production time and labour costs. Furthermore, because bananas are recalcitrant to traditional breeding, there is a constant need for rapid in vitro transformation protocols. To address these challenges, as a proof of concept, our research aims to knockout the INNER NO OUTER (INO) gene, which is responsible for ovule development. Using CRISPR/Cas12a technology, we established an efficient and reproducible in vitro regeneration and transformation system using Embryogenic Cell Suspensions (ECS). The resulting CRISPR-edited plantlets exhibited various mutations, including insertions and deletions (INDELs) within the targeted INO gene. These INDELs resulted in frameshift mutations that triggered premature stop codons. While these genetic changes are expected to render the banana seedless, phenotypic verification is currently underway to confirm the absence of seeds in mature fruit. Significance StatementDespite its superior nutritional profile, the commercial viability of the Bhimkol banana (Musa balbisiana) is restricted due to abundance of seeds (100-150 per fruit). This study employs CRISPR/Cas12a-mediated knockout the INNER NO OUTER (INO) gene in Bhimkol and expected to develop seedless fruits. The resulting plantlets exhibit targeted indels that trigger frameshift mutations, effectively disrupting ovule developmental INO gene.

O_LIRationale: Plants in urban environments often experience heat stress and responses to heat stress often include vegetative and reproductive traits like rosette width and fruit morphology. However, our understanding of natural variation in vegetative and reproductive traits in urban environments is severely limited. C_LIO_LIMethods: We grew an urban weed, Capsella bursa-pastoris, in common garden environments that simulate an urban heat gradient to determine how heat affected growth, survival and reproduction. Additionally, we used geometric morphometric techniques alongside deterministic techniques to quantify variation in C. bursa-pastoris fruit shape and investigated the predictive relationship between fruit shape and seed production. C_LIO_LIKey results: We found that temperatures above 30C act as an environmental constraint on both C. bursa-pastoris fruit shape and reproduction, resulting in malformed fruits and no seed production. However, leaf number and plant survival were unaffected by high urban heat. C_LIO_LIMain conclusions: While plants may grow and survive in the high urban heat, heat could still limit population persistence. C_LI

Prickles on blackberry and raspberry canes make pruning, harvesting, and handling more difficult and can increase labor costs for growers. The trait has been challenging to improve in these clonal crops because it is recessive and linked to undesirable agronomic traits. In blackberry and red raspberry, breeding programs have used recessive mutants at the S locus to generate prickleless cultivars for the last century. In this study, we identified independent loss-of-function mutations in a WUSCHEL-LIKE HOMEOBOX transcription factor, WOX1, as the genetic basis of the prickleless S locus in both blackberry and red raspberry. We mapped the S locus using integrated genome-wide association, bulked segregant analysis, and identity-by-descent analyses informed by breeding pedigrees. Additionally, we generated a genome sequence from Luther Burbanks prickleless blackberry variety Burbank Thornless that contained an additional allele of WOX1. To verify the genes role, we used gene editing to knock out WOX1 in an elite prickled commercial blackberry line. All edited plants were prickleless and lacked glandular trichomes, confirming that WOX1 controls a joint developmental pathway. Other plant traits were unchanged, indicating WOX1 is a specific and safe target for improvement. Gene editing can enable breeders to remove prickles directly from elite varieties, reducing the need for extensive breeding cycles and delivering safer, easier-to-harvest cultivars to growers.

Urban green areas often harbour numerous non-native urban trees, many of which have characteristics that predispose them to escape from cultivation and become potentially invasive. Climate change is expected to exacerbate this risk by creating favourable conditions for species that are currently climatically restricted. The potential risks for invasiveness of urban tree species in continental Europe are not yet known. Here, we provide a comprehensive risk screening of 34 non-native urban tree species in continental Europe, for both current and projected future climate scenarios. Using the Terrestrial Plant Species Invasiveness Screening Kit (TPS-ISK v2.4), we assessed invasion risk based on biogeography, ecology, and projected responses to climate change. Results showed that under current conditions, 10 species (29.4%) were categorised as high risk, 23 (67.6%) as medium risk and one (2.9%) as low risk. The inclusion of climate change projections increased the number of high risk species to 11, with seven species categorised as very high risk. These taxa exhibit strong ecological plasticity, high reproductive performance and broad environmental tolerance, which together with projected warming, emphasises their significant potential for further spread. Our results emphasise the urgent need for early detection, continuous monitoring and proactive management of non-native urban trees in Europe, especially those that are widely used in horticulture and forestry. By integrating invasion biology with climate change risk screening, this study provides an important basis for evidence-based policy and management strategies to mitigate future ecological and economic impacts of invasions by urban trees.

Breeding disease-resistant varieties (DRV) is a central strategy for reducing reliance on phytosanitary products. However, the successful deployment and long-term durability of these cultivars rely on acquiring field data across diverse production conditions, a step that remains frequently neglected, especially in perennial crops. Since 2018, the OSCAR observatory, a network of vineyard plots planted in France with varieties resistant to downy and powdery mildew, the two major pathogens of grapevine, has aimed to close this gap for viticulture. The observatory comprises over 199 commercial plots, covering 127 hectares across diverse agroclimatic conditions, all managed by winegrowers under their own production practices. The observatory currently monitors 30 disease-resistant grapevine varieties, tracking both their agronomic performance and the dynamics of key pathogens. Since 2018, while phytosanitary treatments have been reduced by an average of 79% compared to conventional plots, the incidence of downy and powdery mildew, remain low, even in years highly conducive to these diseases. However, the long-term survey also highlights the decline in efficacy of some resistances to downy mildew and the emergence of black rot, a disease effectively controlled by conventional phytosanitary programs. Beyond acting as a rapid warning system for resistance breakdown, the observatory promotes sustainable disease management in viticulture. It provides valuable insights to winegrowers on effective DRV management. It also delivers actionable feedback to breeders to guide more durable DRV breeding strategies. Highlights- OSCAR observatory monitors 199 plots of grapevine disease resistant varieties (DRV) - Grapevine DRV cuts fungicide uses by 79% while maintaining good disease control - Some resistances efficacy declines against downy mildew, but not powdery mildew - Black rot, a disease usually controlled by fungicide, is rising in OSCAR plots OSCAR provides useful feedback to breeders and winegrowers on DRV management

O_LIStored seeds are crucial repositories of plant genetic diversity. However, long-term storage inevitably causes seed deterioration and loss of viability, and chemical processes within the seeds during storage can influence germination and seedling establishment. Emerging evidence suggests that seed ageing can also affect traits of adult plants, yet the extent to which this phenomenon is relevant across species, particularly for wild plant species with high genetic variation, remains unclear. C_LIO_LITo address this, we focused on 14 grassland species and subjected their seeds to simulated long-term storage by exposing them to artificial ageing conditions (60% rH, 45{degrees}C). We then compared plants grown from the aged seeds with plants from fresh seeds in a common garden experiment. C_LIO_LIArtificially aged seeds germinated later, the developing seedlings had lower survival rates and reduced growth. Adult plants grown from aged seeds flowered later, produced fewer flowers, and had less biomass by the end of the first vegetation period than those from fresh seeds. The effect of the ageing treatment varied between species, but the trend was overall significant across species, with minor differences between perennials and annuals. Interestingly, in perennial plants, the effects vanished or were inverted in the second growing season, with plants growing from aged seeds flowering earlier and producing more biomass. C_LIO_LISynthesis. Our results show that seed storage affects seedling performance, plant growth, and flowering phenology. These direct storage effects should be considered when using stored seeds for species conservation, ecosystem restoration, or evolutionary research relying on stored seeds. C_LI

We present here FennoTraits, which is a dataset of plant functional trait and community composition data which we collected from Fennoscandia across northern Finland, Norway, and Sweden in 2016-2025. This dataset has 42 049 abundance estimations and 155 794 functional trait observations from 10 traits representing 373 vascular plant species collected from 1 235 study sites within seven study areas. The trait measurements consist of size-structural, leaf economic, leaf spectral, and reproductive traits. The species represent the majority of the native vascular plant species that occur at the seven study areas, and many of the species occur in all seven areas across the two biomes and their ecotone: tundra and boreal forests. Each study area has distinct characteristics and a range of habitats: tundra, meadows, wetlands, shrublands, and boreal forests. These areas are under low anthropogenic influence, and many of the sites are within protected areas that are reserved for nature conservation and scientific research. Finally, we provide with this dataset a general description of the main trait patterns and profiles of the northern European flora.

Background and AimsClimate gradients influence seed morphology, emergence, and early life-history traits with cumulative impacts to individual fitness. For ex situ seed collections, which represent an invaluable repository of potential trait information for species management and conservation, climate data can guide preservation of adaptive variation and inform deployment strategies for restoration. Here we leverage a range-wide ex situ seed collection of critically endangered black ash seeds (Fraxinus nigra) to evaluate how climatic gradients shape variation in morphology and early life-history. MethodsTo test how climate of origin, seed morphology, and early life-history interact to impact first year fitness, high-throughput X-ray imaging and neural network-based segmentation were used to quantify variation in seed morphology for 701 maternal lineages spanning 76 populations across the range of F. nigra. Following this, a subset of seeds were used to establish a common garden experiment and quantify variation in emergence, early life-history transitions, and their cumulative impact to first-year survival and growth. ResultsOn average, differences within-population explained [~]43% of the variability in seed morphology, while among-population differences explained [~]14%. This suggests that substantial genetic variation exists within populations for natural selection to act upon and differences have evolved among populations. Climate associations indicated warmer and drier environments predicted heavier seeds with faster developmental transitions and increased first-year height. Together, climate of origin, seed mass, and timing of developmental transitions best predicted cumulative fitness, with populations from more continental environments exhibiting greater survival and first-year height accumulation on average. ConclusionsOverall, these results highlight the importance of climate of origin, seed traits, and early developmental transitions to first-year fitness in a perennial tree species. This work demonstrates how ex situ collections can be used to identify climatically structured trait variation and guide conservation strategies aimed at maintaining adaptive potential under environmental change.

O_LIQuantifying relationships between traits and climate using plants collected from diverse climatic origins, grown under common conditions, potentially provides valuable insights into climate adaptation. C_LIO_LIWe report on fifteen accessions of kangaroo grass (Themeda triandra), a C4 species distributed across Australia, Asia, the Middle East and Africa from the Andropogoneae clade of grasses that is vital to global agriculture. Plants were grown to maturity in glasshouses under two thermal regimes, with ample water supplied. Numerous physiological, "economic" and developmental traits were characterised. C_LIO_LIAs expected, plants grown at 20{degrees}C maxima had lower photosynthetic rates (Asat) and dark respiration rates, reduced leaf expansion, and delayed flowering compared with plants grown at 30{degrees}C. However, surprisingly few traits varied with climate-of-origin: accessions from colder climates had higher Asat alongside lower leaf mass per area, but only when grown at 20{degrees}C; flowering time showed the strongest correlation with site climate, with plants from wetter, warmer or less variable climates taking longer to flower. C_LIO_LIOur findings highlight remarkable phenotypic flexibility in key traits of T. triandra; this flexibility is likely key to its wide distribution. The strong relationship between flowering time and climate-of-origin underscores the importance of reproductive phenology as an adaptive trait. C_LI