Annals of botany最新文献

{"title":"Microhabitat engineers: Seaweed canopies facilitate thermal microclimates across natural and artificial intertidal habitats.","authors":"J Ndaba, M E Hanley, L B Firth, A Lemasson, A M Knights, F Porri, F Bauer","doi":"10.1093/aob/mcag357","DOIUrl":"https://doi.org/10.1093/aob/mcag357","url":null,"abstract":"<p><strong>Background and aims: </strong>Coastal urbanisation and climate change threaten marine biodiversity and increase vulnerability to thermal stress. Canopy-forming fucoid seaweeds are biogenic ecosystem engineers that moderate temperature conditions through their physical morphology and improve habitat conditions in both natural and artificial environments. Consequently, these seaweeds can serve as effective nature-based solutions to buffer the harsh microclimates caused by coastal urbanisation. Despite their ecological importance, the capacity of fucoid canopies to regulate microclimate across contrasting habitats remains understudied, and little is known about the extent to which they can mitigate thermal stress. Here, we assessed their role in modulating temperature and light conditions on a natural rocky shore and an artificial breakwater in south-west England.</p><p><strong>Methods: </strong>At both sites and across three intertidal heights, we quantified spatio-temporal temperature and light microclimates at the quadrat patch scale (25 × 25 cm) and within contrasting microhabitats under fucoid canopies and on exposed rock substrata. Assessments were accompanied by quantification of topographic properties (slope and rugosity) and functional community composition. All surveys were conducted in July under local summer conditions.Key results: We found that fucoid canopies strongly moderated thermal conditions, reducing sub-canopy temperatures by 8.7 - 14.7 °C at the natural site and by 4.6 - 6.4°C at the artificial site, with buffering strength increasing with canopy cover and thickness. Furthermore, microhabitats under fucoids were less thermally variable and more temporally stable than on exposed rock. Canopy thickness was positively correlated with cooler temperatures, particularly under the highest air temperatures. Taxa composition underneath canopies suggested positive ecological responses to the more benign microclimate.</p><p><strong>Conclusion: </strong>Our findings demonstrate that habitat-forming species are key drivers of microclimatic conditions and associated biodiversity, reinforcing the value of nature-based solutions for resilient coastal habitats.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149357068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Handing off iron in plants: from uptake pathways to intracellular chaperones for biofortification.","authors":"Qingnan Chu","doi":"10.1093/aob/mcag355","DOIUrl":"https://doi.org/10.1093/aob/mcag355","url":null,"abstract":"<p><strong>Background: </strong>Plant iron (Fe) homeostasis has been extensively studied at the levels of soil uptake, long-distance transport, storage and deficiency signalling. A less resolved question is how Fe, once it crosses a membrane or is released from an intracellular store, is directed toward specific subcellular destinations and metalloprotein clients.</p><p><strong>Scope: </strong>This Perspective synthesizes recent work on plant Fe acquisition, transporter dynamics, intracellular Fe pools, inter-organelle redistribution, nodule metal delivery and biofortification. It argues that classical transporter- and ligand-centred models remain essential, but may be complemented by selective intracellular routing mechanisms. Legume nodules are highlighted as a high-demand system in which Fe delivery to symbiosomes provides a useful test case for a proposed protein-mediated ionic Fe2+ handoff.</p><p><strong>Conclusions: </strong>Current evidence supports a layered view of plant Fe trafficking in which membrane transport, soluble ligands, redox chemistry, storage compartments and candidate ionic Fe2+ chaperones cooperate to allocate Fe safely and selectively. The recently proposed Medicago truncatula ICHAP proteins provide an emerging model for the direct handoff of ionic Fe2+ between successive membrane-transport steps, a mechanism distinct from the established protein-mediated transfer of preassembled Fe-S clusters by the SUF, ISC and CIA mechineries. A routing-centred framework may help refine biofortification strategies by shifting attention from bulk Fe accumulation toward controlled deposition of nutritionally useful Fe in edible tissues.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149332099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vessel-to-parenchyma connectivity increases towards drier sites and favors survival in tropical dry forest seedling communities.","authors":"Andrés González-Melo, Juan Manuel Cely, Beatriz Salgado-Negret, Camila Pizano, Roy González-M, Katherine Rivera, Julio Abad Ferrer, Juan Pablo Benavides, Álvaro Idarraga, Esteban Moreno, Juliana Puentes, Nancy Pulido, Juan Felipe Solorzano, Maria Natalia Umaña","doi":"10.1093/aob/mcag336","DOIUrl":"https://doi.org/10.1093/aob/mcag336","url":null,"abstract":"<p><strong>Background and aims: </strong>Linking traits with spatial precipitation gradients and demographic performance is critical for predicting how species will respond to frequent and intensified droughts projected under climate change. The degree of connectivity between vessels and parenchyma cells is thought to be a key trait influencing plant hydraulics, particularly resilience to drought stress. However, how this trait is related to growth and survival, and how it varies across precipitation gradients, is largely unknown.</p><p><strong>Methods: </strong>We measured vessel-to-parenchyma connectivity traits, and their relationships with vessel diameter (DH) and wood specific hydraulic conductivity (KS) of 56 seedling species from four species-rich tropical dry forests in Colombia. Next, we assessed how vessel-to-parenchyma connectivity traits changed with site water availability, and how they were related to seedling growth and survival.</p><p><strong>Key results: </strong>Vessel-to-parenchyma connectivity traits were unrelated to DH, KS and growth, which questions their role in promoting efficiency in water transport. However, seedlings in drier sites had higher vessel-to-parenchyma connectivity, and vessel-to-total-parenchyma connectivity was positively related to survival, suggesting a potential role in seedlings' response to drought.</p><p><strong>Conclusions: </strong>These findings suggest that, although not directly related to water transport efficiency and growth, vessel-to-parenchyma connectivity is a relevant trait for tropical dry forest seedlings, as it increased towards drier sites and favored survival, likely by promoting capacitance and osmoregulation.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149332100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From plant blindness to plant awareness: a narrative and visual framework for botanical literacy.","authors":"Luis Navarro","doi":"10.1093/aob/mcag353","DOIUrl":"https://doi.org/10.1093/aob/mcag353","url":null,"abstract":"<p><strong>Background and aims: </strong>Plants underpin terrestrial, freshwater and marine ecosystems, yet they often remain unnoticed in public consciousness, reflecting what is increasingly described as plant awareness disparity. This perceptual and emotional bias limits botanical understanding, weakens conservation engagement, and contributes to broader ecological disconnection. In this Perspective, I argue that narrative and visual storytelling can help shift attention from plant invisibility to plant awareness.</p><p><strong>Scope: </strong>Drawing on cognitive psychology, narrative theory, and environmental education, I propose a conceptual framework linking storytelling inputs (plot, characters, and visual design) to cognitive and emotional mechanisms such as empathy, narrative transportation, and memory consolidation. The framework is illustrated through The Rockbreaker and the Biologist Family, an illustrated story that combines scientific accuracy with artistic expression to communicate the ecology and conservation challenges of the rupicolous genus Petrocoptis. By integrating narrative structure, emotional color transitions, and character-driven engagement, this approach is intended to translate botanical information into accessible and emotionally resonant experiences. Although rooted in an Iberian case study, the framework is designed to be transferable across educational, cultural, and ecological contexts.</p><p><strong>Conclusions: </strong>Embedding storytelling and visual design into botanical communication may strengthen plant awareness, support conservation-oriented attitudes, and help bridge the emotional and intellectual gap between people and plants.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149317365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevation-dependent coordination between stomatal and vein densities among leaf habits and growth forms in a subtropical forest.","authors":"Yu-Mei Yan, Hui Liu, Ze-Tian Liu, Zhong-Xin Duan, Yi Jin, Ze-Xin Fan, Pei-Li Fu, Qi-Qi Li, Zhi-Yong Zhang, Xin Xiong","doi":"10.1093/aob/mcag351","DOIUrl":"https://doi.org/10.1093/aob/mcag351","url":null,"abstract":"<p><strong>Background and aims: </strong>Stomatal and leaf venation traits are important structural components associated with plant gas exchange and water transport, but their variation along environmental gradients may depend on plant functional strategies. We investigated whether stomatal and vein traits exhibit coordinated yet trait-specific patterns across an elevational gradient, and whether such patterns vary with leaf habit and growth form in a subtropical forest.</p><p><strong>Methods: </strong>We examined 12 woody species distributed along a 300-1360 m elevational gradient on Lushan Mountain, China. Stomatal length (SL), stomatal density (SD), and vein density (VD) were quantified from cleared leaves, with species × elevation means used as observational units. Linear mixed-effects models were applied to evaluate associations of traits with elevation, leaf habit (evergreen vs. deciduous), and growth form (shrub vs. tree), and to test elevation-dependent variation in the SD-VD relationship.</p><p><strong>Key results: </strong>Stomatal length and stomatal density showed no significant elevational trends, whereas vein density increased with elevation, indicating contrasting responses among leaf anatomical traits. Stomatal density differed among combinations of leaf habit and growth form, with a significant leaf habit × growth form interaction and higher SD in deciduous trees than in other groups. Across species and elevations, SD was positively associated with VD, but the strength of this relationship varied nonlinearly along the gradient, with the strongest association occurring at intermediate elevations (∼800 m) corresponding to the evergreen-deciduous mixed forest zone.</p><p><strong>Conclusions: </strong>Our findings demonstrate that elevation does not generate uniform changes across leaf anatomical traits. Instead, trait variation depends on environmental context and functional strategies, with leaf habit and growth form jointly influencing stomatal density and stomatal-vein coordination. Considering trait relationships in addition to individual traits provides new insights into how plants organize leaf structure across heterogeneous environments.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149317364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inter-annual variation in fine-scale spatial genetic structure and patterns of density-dependent mating in a population of self-compatible Arabidopsis lyrata.","authors":"Avery Chambers, Braidy Chambers, Katie Pearce, Joanna R Freeland, Marc Stift, Wesley S Burr, Marcel E Dorken","doi":"10.1093/aob/mcag350","DOIUrl":"https://doi.org/10.1093/aob/mcag350","url":null,"abstract":"<p><strong>Background and aims: </strong>Mating patterns in plant populations are shaped jointly by the local availability and relatedness of potential mates, both of which can vary through time in disturbance-prone habitats. We aimed to investigate how a year-to-year change in local plant densities and spatial genetic structure (SGS) influence opportunities for inbreeding and outcrossing in a predominantly self-compatible population of Arabidopsis lyrata subsp. lyrata located in a fore-dune habitat at Rondeau Provincial Park, Ontario.</p><p><strong>Methods: </strong>We mapped plants in 40 patches, each centred on a focal plant, over two consecutive years, quantified SGS with kinship-distance analyses of 27 and 34 focal plants in the first and second years, respectively, and estimated multilocus rates of outcrossing and biparental inbreeding from 128 and 177 progeny, respectively.</p><p><strong>Key results: </strong>Across surveyed patches, plant density increased more than five-fold between years, coinciding with a marked decline in fine-scale SGS (Sp = 0.130 in year one; Sp = -0.014 in year two). Despite similar population-wide outcrossing rates in both years (tm = 0.45 in 2021; tm = 0.49 in 2022), outcrossing was positively associated with neighbourhood density in the lower-density year but showed no density dependence when densities were high in the second year. In both years, 15-20% of outcrossed seeds were produced by mating among relatives, indicating substantial biparental inbreeding.</p><p><strong>Conclusions: </strong>Our results suggest that recruitment pulses in dynamic dune habitats can rapidly weaken SGS while simultaneously altering the scale at which density governs mating patterns. More generally, they highlight how short-term temporal variation in population size can modulate the local availability and relatedness of mates within plant populations.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149317366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The interplay between root morphological plasticity and mucilage production facilitates drought adaptation across soil textures.","authors":"Mohanned Abdalla, Mutez Ali Ahmed","doi":"10.1093/aob/mcag349","DOIUrl":"https://doi.org/10.1093/aob/mcag349","url":null,"abstract":"<p><strong>Background and aims: </strong>The interplay between root functional traits, such as mucilage secretion and root morphology, in plant response to combined edaphic and atmospheric drought, particularly under contrasting soil texture, remains unknown.</p><p><strong>Methods: </strong>We leveraged two cowpea genotypes differing in mucilage production (high mucilage [HM] and low mucilage [LM]) to investigate plant water use and root morphological responses to two contrasting soil textures (sand and loam).</p><p><strong>Key results: </strong>Both genotypes adapted their root morphological traits in response to soil textures. In contrast to HM, the LM genotype exhibited a twofold increase in root length in sand compared to loam, which resulted in a fourfold increase in root-to-shoot area ratio and specific root length. During soil drying and increasing vapor pressure deficit (VPD), the HM genotype exhibited transpiration limitation at lower transpiration rates compared to LM, hereby promoting more conservative water use, particularly in sand. We further found that the critical soil moisture (SM) threshold, the SM at which plants started to downregulate transpiration, is soil-texture specific.</p><p><strong>Conclusions: </strong>Our findings suggest that high mucilage production promotes water saving strategy during soil drying. Increasing root length and high root-to-shoot area ratio emerge as compensatory drought-adaptive strategies to coarse-textured soil, especially in LM genotype. Future studies should investigate the interplay between different root functional traits across species and climates.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149294020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Life in the fast lane: early-successional species show four different strategies.","authors":"Jazz J M Kok, Frans Bongers, Lucy Amissah, Alexander Baah, Tomonari Matsuo, Lourens Poorter","doi":"10.1093/aob/mcag344","DOIUrl":"https://doi.org/10.1093/aob/mcag344","url":null,"abstract":"<p><strong>Background and aims: </strong>Global land-use change and climate change are transforming tropical forests into regrowing secondary forests, where early-successional species play a crucial role by colonizing abandoned lands and paving the way for later-successional species. While often considered a homogeneous group with uniformly fast strategies, this study evaluates the diversity of early-successional strategies from Ghanaian tropical dry and wet forests.</p><p><strong>Methods: </strong>We selected 30 early-successional species from Ghanaian dry and wet forests differing in leaf habit (deciduous vs. evergreen), and measured wood density and 12 morphological and physiological leaf traits related to drought adaptation and resource acquisition. Traits were compared between forest types and leaf habits using two-way ANOVA, and multivariate analyses identified trait associations and trade-offs.</p><p><strong>Key results: </strong>Dry forest species were more drought-tolerant and had slower gas exchange rates than wet forest species, reflecting reduced water use under limited water availability. Multivariate trait analysis showed that early-successional species span a two-dimensional trait space with two main trade-offs: (1) drought tolerance (i.e. high absolute leaf turgor loss point and wood density) versus gas exchange, and (2) investment in leaf structural carbon versus nutrients. The two axes defined four strategies: species that (1) tolerate drought and have tough leaves (\"tolerant-and-tough\"), (2) tolerate drought and have nutrient-rich leaves (\"tolerant-and-rich\"), (3) grow rapidly and have tough leaves (\"fast-and-tough\"), and (4) grow rapidly and have nutrient-rich leaves (\"fast-and-rich\").</p><p><strong>Conclusions: </strong>Early-successional species followed four diverse strategies rather than converging on a single, fast-growing, acquisitive strategy. Their strategies also extended beyond the commonly described fast-slow gradient, with unexpected trait combinations reflecting the contrasting demands of rapid carbon gain and water conservation during early succession. Such variation may steer successional trajectories because different environmental conditions select for different early-successional strategies.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149284708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of parallel multi-dimensional phenotypic reorganization in Brassica incana on two Mediterranean islands.","authors":"Giovanni Scopece, Lucrezia Laccetti","doi":"10.1093/aob/mcag347","DOIUrl":"https://doi.org/10.1093/aob/mcag347","url":null,"abstract":"<p><strong>Background and aims: </strong>Island populations represent natural evolutionary experiments, often showing predictable divergence in life-history strategies (i.e., island syndrome). The multi-dimensional expression of this island syndrome in plants, spanning vegetative morphology, floral architecture, and seed provisioning, and its downstream consequences for offspring performance remains poorly characterized. Here, we aim to investigate whether island colonization reshapes phenotypic traits and reproductive investment strategies in insular Brassica incana populations occurring on two proximate Mediterranean islands.</p><p><strong>Methods: </strong>Focusing on two mainland-insular population pairs across contrasting substrates (volcanic and limestone), we integrated genomic, phenotypic, and experimental approaches. We measured vegetative, floral, and reproductive traits across two flowering seasons, estimated standardized linear selection gradients to identify which phenotypic traits are under selection, and estimated the strength of phenotypic integration, i.e., the correlation among phenotypic traits, within each population. Finally, we tested the effect of seed mass on germination probability and early seedling performance in a controlled experiment.</p><p><strong>Key results: </strong>Insular populations showed moderate genomic differentiation from mainland populations and comparable levels of genetic diversity. Across both mainland-insular comparisons and both flowering seasons, insular populations showed larger leaf areas, larger corollas, a higher ratio of reproductive to aboveground vegetative biomass proxy, more seeds per fruit, and heavier seeds than mainland populations, while producing fewer leaves and fewer fruits, revealing different allocation trade-offs. Corolla size was under significant positive selection in insular populations. Seed mass did not predict germination probability, but was a strong positive predictor of seedling biomass under home-soil conditions. Phenotypic integration was overall low across all populations.</p><p><strong>Conclusions: </strong>Island colonization in B. incana shows a consistent multi-dimensional syndrome across two independent colonization events and across years. This replicated demonstration expands our understanding of the island syndrome in plants, while revealing small and proximate Mediterranean islands as valuable, underexplored contexts for studying insular evolution.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149294159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developmental constraints on bisexuality in compound cones of Ephedra (Gnetales) and implications on the independent origin of bisexual flowers.","authors":"Dmitry D Sokoloff, Stefanie M Ickert-Bond","doi":"10.1093/aob/mcag345","DOIUrl":"https://doi.org/10.1093/aob/mcag345","url":null,"abstract":"<p><strong>Background and aims: </strong>In Ephedra foeminea, Welwitschia and Gnetum spp. (representing all genera of extant Gnetales) male cones have sterile ovules releasing pollination drops to attract pollinators. This condition is unknown in other gymnosperms and resembles the independently evolved bisexuality of angiosperm flowers. Patterns of bisexuality are insufficiently documented in Ephedra, despite their historical importance in Wettstein's pseudanthial theory of the origin of angiosperm flowers.</p><p><strong>Methods: </strong>We combine original light and scanning electron microscopy data on cone structure and development in Ephedra, field observations in Israel and the USA, and a literature review.</p><p><strong>Key results: </strong>Structurally bisexual cones are reported for more than ten of the 57 extant species of Ephedra. Sterile ovules of E. foeminea, Welwitschia and Gnetum exhibit strong and taxon-specific differences from fertile ovules. Occasional bisexual cones of other Ephedra species do not show a functional link to entomophily and have no constraints against male or female fertility. Male organ development is delayed or fully suppressed in the node preceding the ovule(s) in bisexual cones of Ephedra. A terminal reproductive unit rarely develops in bisexual cones.</p><p><strong>Conclusions: </strong>Cone bisexuality, monoecy and possibly insect pollination are homoplastic in Ephedra. Ovule dimorphism in E. foeminea provides a system to study how key morphological characteristics are regulated in the Gnetales. The suppression or developmental retardation of the uppermost male organs in bisexual cones may be related to the compound nature of the cone and branching suppression below the female zone. In addition to theories interpreting the angiosperm flower as a simple or compound strobilus homologue, the present study highlights the need to test an inverted branching hypothesis, namely, that angiosperm flowers are homologous to a simple strobilus in the androecium, but to a compound cone in the gynoecium.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149284697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}