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AbstractAs a key component of lightweight impact-protection devices, thin-walled structures with marvelous specific energy absorption (SEA) have attracted wide attention. Inspired by leaf venation in royal water lily, a hybrid multi-cell thin-walled structure with fractal and hierarchy architectures is proposed. Its crashworthiness is compared with traditional cylinder by combining finite element simulation and experiment, and corresponding mechanism is revealed. The results show that due to more folds and smaller folded wavelength, the venation-like structure exhibits better crashworthiness than the cylinder. Increasing the initial bifurcation number and hierarchy level of venation-like structure will introduce massive corner constraints, especially the hierarchy level, which benefits folding deformation and improving effectively crashworthiness. Further, a fully hybrid venation-like structure is designed by introducing gradient architecture. With the increase of length-gradient or thickness-gradient, the SEA first linearly increases and then slightly decreases. Under the optimal length-gradient, majority of area exhibits high internal energy. By taking the gradient length and thickness simultaneously, a kind of hybrid deformation mode with quasi-uniform small folding and overall large folding appears, where multiple small folds interacts strongly, achieving good load-bearing capacity. The optimal SEA of venation-like structure is 81.5% higher than that of the cylinder. [ABSTRACT FROM AUTHOR]

Nature-inspired microfluidic networks are revolutionizing microphysiological systems, allowing for the precise emulation of human physiology. This article delves into the fabrication techniques of leaf-venation-inspired (LVI) microfluidic networks and explores their transformative applications in organ-on-a-chip and tissue engineering, showcasing their pivotal role in advancing biomedical research. [ABSTRACT FROM AUTHOR]

The classification of Mussaenda L. has been controversial due to the complex interspecific variation and hybridization within the genus. In order to explore the taxonomical significance of leaf venation characteristics between Mussaenda and its relative genera (Schizomussaenda Li and Psudomussaenda Wernham), and to provide data for the identification, development and utilization when they were regarded as the medical and garden plant resources, the leaf venation characteristics of 22 species of this group were observed by using the cleaning method. The cluster analysis was carried out based on the characteristics of leaf venation, and a classification key of the species was compiled. The results were as follows: (1) The characteristics of the leaf venation of Mussaenda and its relative genera had consistency, which were mainly reflected on that the primary veins were all pinnate, the frequency of inter-secondary veins was less than one per areolation, the angles between the major secondary veins and the midveins were acute, the tertiary veins were mostly penetrating, and the arrangement of the areolation were all irregular. (2) The characteristics of the leaf venation with taxonomic value among genera or species within genera included the type of major secondary vein venation type, the angle between major secondary vein and midvein, the major secondary vein spacing, the connection between major secondary vein and midvein, the existence of inter-secondary vein and intramarginal secondary vein, the penetration type of intercostal tertiary vein, the type of quaternary vein, the branching of freely ending veinlet, and the areole development. (3) According to the cluster analysis, 22 species of this group were clustered into 12 branches, and Schizomussaenda and Psudomussaenda were not clustered into one branch respectively, showing a relatively close genetic relationship. In conclusion, the leaf venation characteristics of Mussaenda and its related taxa can provide new information for the classification of the plants. [ABSTRACT FROM AUTHOR]

Herbivory can impact gas exchange, but the causes of interspecific variation in response remain poorly understood. We aimed to determine (1) what effects does experimental herbivory damage to leaf midveins have on leaf gas exchange and, (2) whether changes in leaf gas exchange after damage was predicted by leaf mechanical or venation traits. We hypothesized that herbivory-driven impacts on leaf gas exchange would be mediated by (1a/1b) venation networks, either by more vein resistance, or possibly trading off with other structural defenses; (2a/2b) or more reticulation (resilience, providing more alternate flow pathways after damage) or less reticulation (sectoriality, preventing spread of reduced functionality after damage). We simulated herbivory by damaging the midveins of four leaves from each of nine Sonoran Desert species. We then measured the percent change in photosynthesis (ΔAn%), transpiration (ΔEt%) and stomatal conductance (Δgsw%) between treated and control leaves. We assessed the relationship of each with leaf venation traits and other mechanical traits. ΔAn% varied between +10 % and -55%, similar to ΔEt% (+27%, -54%) and Δgsw% (+36%, -53%). There was no tradeoff between venation and other structural defenses. Increased damage resilience (reduced ΔAn%, ΔEt%, Δgsw%) was marginally associated with lower force-to-tear (P < 0.05), and higher minor vein density (P < 0.10) but not major vein density or reticulation. Leaf venation networks may thus partially mitigate the response of gas exchange to herbivory and other types of vein damage through either resistance or resilience.

Summary: We investigated the mining mode of insect feeding, involving larval consumption of a plant's internal tissues, from the Middle Jurassic (165 million years ago) Daohugou locality of Northeastern China. Documentation of mining from the Jurassic Period is virtually unknown, and results from this time interval would address mining evolution during the temporal gap of mine–seed plant diversifications from the previous Late Triassic to the subsequent Early Cretaceous.Plant fossils were examined with standard microscopic procedures for herbivory and used the standard functional feeding group–damage‐type system of categorizing damage. All fossil mines were photographed and databased.We examined 2014 plant specimens, of which 27 occurrences on 14 specimens resulted in eight, new, mine damage types (DTs) present on six genera of bennettitalean, ginkgoalean, and pinalean gymnosperms.Three conclusions emerge from this study. First, these mid‐Mesozoic mines are morphologically conservative and track plant host anatomical structure rather than plant phylogeny. Second, likely insect fabricators of these mines were three basal lineages of polyphagan beetles, four basal lineages of monotrysian moths, and a basal lineage tenthredinoid sawflies. Third, the nutrition hypothesis, indicating that miners had greater access to nutritious, inner tissues of new plant lineages, best explains mine evolution during the mid‐Mesozoic. See also the Commentary on this article by McLoughlin & Santos, 242: 2391–2393. [ABSTRACT FROM AUTHOR]

Using 33 specimens collected from across their range in Turkey, we demonstrate that the subspecies of Prunus microcarpa C.A.Mey react very differently to altitude. We first outline a simplified, flexible protocol for sectioning and removing the epidermis of small, difficult‐to‐image leaves for leaf vein studies. We then used venation analysis software to evaluate the two subspecies of this wild cherry in relation to altitude. We also found key differences in venation features between short‐shoot and long‐shoot leaves for each taxon. Differences include statistically significant negative correlation between vein density, and positive correlation between areole area and altitude in long‐shoot leaves of Prunus microcarpa subsp. microcarpa, while its short‐shoot leaves had a positive relationship between maximum areole area, and negative relationship between vein density, numbers of veins and endpoints. Meanwhile, P. microcarpa subsp. tortuosa (Boiss. & Hausskn.) Browicz recorded trends that were largely opposite of this, but beside vein thickness and areole area, were not statistically significant. This difference may be part of each taxon's overarching syndrome of anatomical and morphological adaptations to its external environment. Research Highlights: Features of vein density and thickness fell, while areole area and vein length rose with altitude in P. microcarpa.P. microcarpa subsp. tortuosa showed opposite trends, but reacted less strongly to altitude.Short‐shoot and long‐shoot have significantly different venation parameters.Using sections proportionate to leaf size is useful to compare venation of leaves that vary due to dimorphism.We discuss protocol strategies for imaging of difficult leaves for venation analyses. [ABSTRACT FROM AUTHOR]

The dataset contains leaf venation architecture and functional traits for a phylogenetically diverse set of 122 plant species (including ferns, basal angiosperms, monocots, basal eudicots, asterids, and rosids) collected from the living collections of the University of California Botanical Garden at Berkeley (37.87° N, 122.23° W; CA, USA) from February to September 2021. The sampled species originated from all continents, except Antarctica, and are distributed in different growth forms (aquatic, herb, climbing, tree, shrub). The functional dataset comprises 31 traits (mechanical, hydraulic, anatomical, physiological, economical, and chemical) and describes six main leaf functional axes (hydraulic conductance, resistance and resilience to damages caused by drought and herbivory, mechanical support, and construction cost). It also describes how architecture features vary across venation networks. Our trait dataset is suitable for (1) functional and architectural characterization of plant species; (2) identification of venation architecture‐function trade‐offs; (3) investigation of evolutionary trends in leaf venation networks; and (4) mechanistic modeling of leaf function. Data are made available under the Open Data Commons Attribution License. [ABSTRACT FROM AUTHOR]

Arabidopsis thaliana ecotypes adapted to native habitats with different daylengths, temperatures, and precipitation were grown experimentally under seven combinations of light intensity and leaf temperature to assess their acclimatory phenotypic plasticity in foliar structure and function. There were no differences among ecotypes when plants developed under moderate conditions of 400 µmol photons m−2 s−1 and 25 °C. However, in response to more extreme light or temperature regimes, ecotypes that evolved in habitats with pronounced differences in either the magnitude of changes in daylength or temperature or in precipitation level exhibited pronounced adjustments in photosynthesis and transpiration, as well as anatomical traits supporting these functions. Specifically, when grown under extremes of light intensity (100 versus 1000 µmol photons m−2 s−1) or temperature (8 °C versus 35 °C), ecotypes from sites with the greatest range of daylengths and temperature over the growing season exhibited the greatest differences in functional and structural features related to photosynthesis (light- and CO2-saturated capacity of oxygen evolution, leaf dry mass per area or thickness, phloem cells per minor vein, and water-use efficiency of CO2 uptake). On the other hand, the ecotype from the habitat with the lowest precipitation showed the greatest plasticity in features related to water transport and loss (vein density, ratio of water to sugar conduits in foliar minor veins, and transpiration rate). Despite these differences, common structure–function relationships existed across all ecotypes and growth conditions, with significant positive, linear correlations (i) between photosynthetic capacity (ranging from 10 to 110 µmol O2 m−2 s−1) and leaf dry mass per area (from 10 to 75 g m−2), leaf thickness (from 170 to 500 µm), and carbohydrate-export infrastructure (from 6 to 14 sieve elements per minor vein, from 2.5 to 8 µm2 cross-sectional area per sieve element, and from 16 to 82 µm2 cross-sectional area of sieve elements per minor vein); (ii) between transpiration rate (from 1 to 17 mmol H2O m−2 s−1) and water-transport infrastructure (from 3.5 to 8 tracheary elements per minor vein, from 13.5 to 28 µm2 cross-sectional area per tracheary element, and from 55 to 200 µm2 cross-sectional area of tracheary elements per minor vein); (iii) between the ratio of transpirational water loss to CO2 fixation (from 0.2 to 0.7 mol H2O to mmol−1 CO2) and the ratio of water to sugar conduits in minor veins (from 0.4 to 1.1 tracheary to sieve elements, from 4 to 6 µm2 cross-sectional area of tracheary to sieve elements, and from 2 to 6 µm2 cross-sectional area of tracheary elements to sieve elements per minor vein); (iv) between sugar conduits and sugar-loading cells; and (v) between water conducting and sugar conducting cells. Additionally, the proportion of water conduits to sugar conduits was greater for all ecotypes grown experimentally under warm-to-hot versus cold temperature. Thus, developmental acclimation to the growth environment included ecotype-dependent foliar structural and functional adjustments resulting in multiple common structural and functional relationships. [ABSTRACT FROM AUTHOR]

The data set contains images of leaf venation networks obtained from tree species in Malaysian Borneo. The data set contains 726 leaves from 295 species comprising 50 families, sampled from eight forest plots in Sabah. Image extents are approximately 1 × 1 cm, or 50 megapixels. All images contain a region of interest in which all veins have been hand traced. The complete data set includes over 30 billion pixels, of which more than 600 million have been validated by hand tracing. These images are suitable for morphological characterization of these species, as well as for training of machine-learning algorithms that segment biological networks from images. Data are made available under the Open Data Commons Attribution License. You are free to copy, distribute, and use the database; to produce works from the database; and to modify, transform, and build upon the database. You must attribute any public use of the database, or works produced from the database, in the manner specified in the license. For any use or redistribution of the database, or works produced from it, you must make clear to others the license of the database and keep intact any notices on the original database.

Bu çalışmada farklı bir yaklaşımla yeni orkide sınıflandırmalarını test etmek, yaprak damar deseninin bu sınıflandırmaları ne derecede temsil ettiğini araştırmak ve diagnostik olan damarlanma özelliklerinin belirlenmesi amaçlanmıştır. Sistematik kategorisi değişen türler ile birlikte Orchis üyelerinden simpatrik yayılış gösteren 8 tür araştırmaya konu edilmiştir. Bitki örnekleri Karadeniz Bölgesi’ndeki çeşitli lokalitelerden toplanmıştır. Olgun yapraklara saydamlaştırma ve boyama işlemi uygulanarak stereo mikroskopta fotoğraflanmış, damar ve areol yapılarına ait 15 morfometrik özellik analiz edilmiştir. Yaprak damar özellikleri açısından türler arasındaki farklılığın anlamlı olup olmadığını test etmek amacıyla oneway ANOVA uygulanmış ve analiz sonucunda gruplandırmada etkili olanlar ayrım analizi ile belirlenmiştir. Analiz sonucunda yeni sınıflandırmayı destekleyen veriler elde edilmiştir. Neotinea üyelerini diğer taksonlardan ayıran özellikler arasında areollerin çevresi, daireselliği, en/boy oranı gibi areol özellikleri ön plana çıkarken Anacamptis üyeleri birim alandaki damar yoğunluğu, damar uzunluğu gibi özellikler açısından farklılaşmaktadır. Bu sonuçlar damarlanmanın topolojik ve morfometrik karakterlerinin orkidelerin sistematik ve filogenetik ilişkilerini yansıtabileceğini ve özellikle problemli gruplarda sınıflandırmaya ilişkin problemlerin çözümünde etkili olabileceğini işaret etmektedir.

Leaf morphoanatomy can provide useful information for the taxonomy of morphologically similar species or the recognition of infraspecific taxa. Here, we evaluated the taxonomic utility of leaf morphological and anatomical characters for the recognition of distinct morphologies currently placed under Oxalis polymorpha Mart. ex Zucc., a highly polymorphic species of Oxalis from the Brazilian Atlantic Forest. We analyzed leaves of 13 specimens gathered from five populations throughout the species' geographic distribution. Leaf samples were analyzed under light and scanning electron microscopy. We observed differences in the leaf blade venation patterns, in the indumentum of petioles and leaf blades, in the pulvinar vascular tissue configuration, and in the midrib tissue organization. The variation in these characters allowed us to recognize four different morphotypes among these samples. These morphotypes are geographically disjunct and differ among each other in additional morphological features, such as leaf arrangement along the stem, leaflet shape, inflorescence position, petal color, and fruit shape. Oxalis polymorpha is a good candidate for investigating if phylogenetic relationships support recognition of each of its morphotypes at the species level. [ABSTRACT FROM AUTHOR]

Automatic classification of the plants is growing area of association with computer science and Botany, it has attracted many researchers to subsidize plant classification using image processing and machine learning techniques. Plants can be classified using number of traits such as leaf color, flowers, leaves, roots, leaf shape, leaf size etc. highly depends upon feature selection methods. However extraction of features from selected trait is most significant state in classification. State-of-the-art classification can be achieved by using leaf characteristics such as leaf venation patterns, leaf spectral signatures, leaf color, leaf shape, etc. This paper describes multimodal plant classification system using leaf venation patterns and its spectral signatures as a significant features. This paper shows that the feature fusion can be used to achieve efficient plant identification. The accuracy of identification for leaf spectral data, leaf venation features and HOG features is validated, it signifies that feature fusion technique performs better than that of non-imaging spectral signatures features only, with recognition result of 98.03% GAR and 93.51% GAR, respectively.

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We compare the solutions of two systems of partial differential equations (PDEs), seen as two different interpretations of the same model which describes the formation of complex biological networks. Both approaches take into account the time evolution of the medium flowing through the network, and we compute the solution of an elliptic–parabolic PDE system for the conductivity vector m, the conductivity tensor C and the pressure p. We use finite differences schemes in a uniform Cartesian grid in a spatially two-dimensional setting to solve the two systems, where the parabolic equation is solved using a semi-implicit scheme in time. Since the conductivity vector and tensor also appear in the Poisson equation for the pressure p, the elliptic equation depends implicitly on time. For this reason, we compute the solution of three linear systems in the case of the conductivity vector m ∈ R 2 and four linear systems in the case of the symmetric conductivity tensor C ∈ R 2 × 2 at each time step. To accelerate the simulations, we make use of the Alternating Direction Implicit (ADI) method. The role of the parameters is important for obtaining detailed solutions. We provide numerous tests with various values of the parameters involved to determine the differences in the solutions of the two systems. [ABSTRACT FROM AUTHOR]

Background and Aims Ferns are the second largest group of vascular plants and are distributed nearly worldwide. Although ferns have been integrated into some comparative ecological studies focusing on hydathodes, there is a considerable gap in our understanding of the functional anatomy of these secretory tissues that are found on the vein endings of many fern leaves. In this study, we aimed to investigate the phylogenetic distribution, structure and function of fern hydathodes. Methods We performed a global review on fern hydathodes and their phylogenetic distribution, carried out an ancestral character state reconstruction, and studied the structure, guttation and elemental composition of salt residues of eight species, and the diurnal patterns of xylem pressure of two species. Key Results Hydathodes are known from 1189 fern species, 92 genera and 19 families of 2 orders, Equisetales and Polypodiales. Stochastic character mapping indicated multiple gains and losses of hydathodes at the genus level, occurring especially during the last 50 million years of fern evolution. Hydathodes were located on the adaxial leaf surface and characterized by a cytoplasm-rich, pore-free epidermis, and became functional for several weeks after nearly complete leaf expansion. In two species, positive xylem pressure built up at night, potentially facilitating guttation. Guttation fluid was rich in Ca and often Si, but also contained P, Mg, Na and Al. Conclusions Stochastic character mapping and the structural and functional diversity of hydathodes indicate multiple origins, and their presence/absence in closely related taxa implies secondary losses during fern evolution. Positive xylem pressure and high air humidity play an important role as drivers of guttation. Hydathodes may contribute to the regulation of leaf nutrient stoichiometry by the release of excessive compounds and minerals other than waste products, but the presence of essential chemical elements in salt residues also indicates possible leakage. [ABSTRACT FROM AUTHOR]

ABSTRACT Leaf venation has not been widely used in taxonomic integrative works, although some potential in delimiting taxa has been reported. Hyptidendron, a neotropical genus with 20 species, seemed to present some variation in leaf venation patterns, which we sought to further investigate. A number of different herbaria were consulted, and herborized leaves were diaphanized for 20 species of Hyptidendron and a set of unidentified material. The taxa were classified according to their venation patterns. Hyptidendron possesses pinnate semicraspedodromous venation with reticulate irregular tertiary, quaternary and quinternary veins. Freely Ending Veinlets show some variation between species but without clear taxonomic importance. Otherwise, perimarginal veins were greatly informative, being present only in the unidentified material. Together with differences from other species of the genus in leaf shape, margins shape, calyx indumentum and petiole size, we hypothesize the unidentified material as a new species: Hyptidendron cerradoense, described here. We provide a full description, illustration, a distribution map, a preliminary conservation assessment and comments on both the taxonomy and ecology of the new species. Our study supports the importance of leaf venation for taxonomic studies, even in smaller genera.

Arabidopsis thaliana ecotypes adapted to native habitats with different daylengths, temperatures, and precipitation were grown experimentally under seven combinations of light intensity and leaf temperature to assess their acclimatory phenotypic plasticity in foliar structure and function. There were no differences among ecotypes when plants developed under moderate conditions of 400 µmol photons m−2 s−1 and 25 °C. However, in response to more extreme light or temperature regimes, ecotypes that evolved in habitats with pronounced differences in either the magnitude of changes in daylength or temperature or in precipitation level exhibited pronounced adjustments in photosynthesis and transpiration, as well as anatomical traits supporting these functions. Specifically, when grown under extremes of light intensity (100 versus 1000 µmol photons m−2 s−1) or temperature (8 °C versus 35 °C), ecotypes from sites with the greatest range of daylengths and temperature over the growing season exhibited the greatest differences in functional and structural features related to photosynthesis (light- and CO2-saturated capacity of oxygen evolution, leaf dry mass per area or thickness, phloem cells per minor vein, and water-use efficiency of CO2 uptake). On the other hand, the ecotype from the habitat with the lowest precipitation showed the greatest plasticity in features related to water transport and loss (vein density, ratio of water to sugar conduits in foliar minor veins, and transpiration rate). Despite these differences, common structure–function relationships existed across all ecotypes and growth conditions, with significant positive, linear correlations (i) between photosynthetic capacity (ranging from 10 to 110 µmol O2 m−2 s−1) and leaf dry mass per area (from 10 to 75 g m−2), leaf thickness (from 170 to 500 µm), and carbohydrate-export infrastructure (from 6 to 14 sieve elements per minor vein, from 2.5 to 8 µm2 cross-sectional area per sieve element, and from 16 to 82 µm2 cross-sectional area of sieve elements per minor vein); (ii) between transpiration rate (from 1 to 17 mmol H2O m−2 s−1) and water-transport infrastructure (from 3.5 to 8 tracheary elements per minor vein, from 13.5 to 28 µm2 cross-sectional area per tracheary element, and from 55 to 200 µm2 cross-sectional area of tracheary elements per minor vein); (iii) between the ratio of transpirational water loss to CO2 fixation (from 0.2 to 0.7 mol H2O to mmol−1 CO2) and the ratio of water to sugar conduits in minor veins (from 0.4 to 1.1 tracheary to sieve elements, from 4 to 6 µm2 cross-sectional area of tracheary to sieve elements, and from 2 to 6 µm2 cross-sectional area of tracheary elements to sieve elements per minor vein); (iv) between sugar conduits and sugar-loading cells; and (v) between water conducting and sugar conducting cells. Additionally, the proportion of water conduits to sugar conduits was greater for all ecotypes grown experimentally under warm-to-hot versus cold temperature. Thus, developmental acclimation to the growth environment included ecotype-dependent foliar structural and functional adjustments resulting in multiple common structural and functional relationships.

Premise: Angiosperm leaves present a classic identification problem due to their morphological complexity. Computer‐vision algorithms can identify diagnostic regions in images, and heat map outputs illustrate those regions for identification, providing novel insights through visual feedback. We investigate the potential of analyzing leaf heat maps to reveal novel, human‐friendly botanical information with applications for extant‐ and fossil‐leaf identification. Methods: We developed a manual scoring system for hotspot locations on published computer‐vision heat maps of cleared leaves that showed diagnostic regions for family identification. Heat maps of 3114 cleared leaves of 930 genera in 14 angiosperm families were analyzed. The top‐5 and top‐1 hotspot regions of highest diagnostic value were scored for 21 leaf locations. The resulting data were viewed using box plots and analyzed using cluster and principal component analyses. We manually identified similar features in fossil leaves to informally demonstrate potential fossil applications. Results: The method successfully mapped machine strategy using standard botanical language, and distinctive patterns emerged for each family. Hotspots were concentrated on secondary veins (Salicaceae, Myrtaceae, Anacardiaceae), tooth apices (Betulaceae, Rosaceae), and on the little‐studied margins of untoothed leaves (Rubiaceae, Annonaceae, Ericaceae). Similar features drove the results from multivariate analyses. The results echo many traditional observations, while also showing that most diagnostic leaf features remain undescribed. Conclusions: Machine‐derived heat maps that initially appear to be dominated by noise can be translated into human‐interpretable knowledge, highlighting paths forward for botanists and paleobotanists to discover new diagnostic botanical characters. [ABSTRACT FROM AUTHOR]

Automatic classification of the plants is growing area of association with computer science and Botany, it has attracted many researchers to subsidize plant classification using image processing and machine learning techniques. Plants can be classified using number of traits such as leaf color, flowers, leaves, roots, leaf shape, leaf size etc. highly depends upon feature selection methods. However extraction of features from selected trait is most significant state in classification. State-of-the-art classification can be achieved by using leaf characteristics such as leaf venation patterns, leaf spectral signatures, leaf color, leaf shape, etc. This paper describes multimodal plant classification system using leaf venation patterns and its spectral signatures as a significant features. This paper shows that the feature fusion can be used to achieve efficient plant identification. The accuracy of identification for leaf spectral data, leaf venation features and HOG features is validated, it signifies that feature fusion technique performs better than that of non-imaging spectral signatures features only, with recognition result of 98.03% GAR and 93.51% GAR, respectively. [ABSTRACT FROM AUTHOR]

With the aim of recognizing and identifying both fertile and sterile specimens of Ocotea from the Brazilian state of Bahia, we analyzed the leaf venation pattern of 55 species, 21 of them being described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa. [ABSTRACT FROM AUTHOR]

Aims We compared vein and stomatal traits of seedlings and adults of three Mediterranean Quercus species. Previous work suggests that gas-exchange rates tend to be higher at the seedling stage than in adults. Our objective was to determine whether vein and stomatal traits vary throughout whole-plant ontogeny in parallel with the changes in gas-exchange rates. We addressed the following alternative hypotheses: hypothesis 1—seedlings show higher vein and stomatal densities than adults; and hypothesis 2—seedlings have lower investments in vascular tissues to reduce construction costs. Methods Ten specimens from each growth stage were randomly sampled for each species in a location in central-western Spain. We measured mean stomatal and vein traits (size and number of stomata per unit of leaf area, vein density, vein volume, vein to epidermis distance), leaf mass per area and lamina thickness. Important Findings Minor vein density and vein volume per area increased with tree age, which seems inconsistent with the ontogenetic trends in gas-exchange rates. This discrepancy is in support of our hypothesis 2, and it suggests that, at the seedling stage, reducing investments in vascular tissues in benefit of maximizing growth rates is a priority. Larger interveinal distances in seedlings were compensated by smaller vein to epidermis distances. The thin leaves of the seedlings may thus constitute as a necessary trait for achieving shorter path length distances for the transport of water to evaporation sites without the need for a strong investment in costly vascular tissues. [ABSTRACT FROM AUTHOR]

In the present study leaf venation types of 30 Saxifraga L. species, found in Indian Western Himalaya, were studied. Out of these, leaf venation patterns of 20 species were not previously studied. In total, five major types of leaf venations- acrodomous (perfect-basal; perfect-suprabasal; imperfect-suprabasal), camptodromous (eucamptodromous), campylodromous, hyphodromous, and palinactinodromous – were recorded. Section Micranthes show palinactinodromous; section Ciliatae show mainly acrodromous; section Mesogyne show palinactinodromous; and sect. Porphyrion show acrodromous, eucamptodromous and hyphodromous types of venation. Palinactinodromous appear as the ancestral venation type.

With the aim of recognizing and identifying both fertile and sterile specimens of Lauraceae from the Reserva Natural Vale, Linhares, we analyzed the leaf venation pattern of 20 species belonging to 11 genera. The venation patterns of 12 species are described and illustrated for the first time here. A dichotomous identification key was built from a matrix of 12 venation characters with 38 states, which allowes to distinguish the taxa. [ABSTRACT FROM AUTHOR]

The main role of leaf venation is to supply water across the photosynthetic surface to keep stomata open and allow access to atmospheric CO2 despite evaporative demand. The optimal uniform delivery of water occurs when the distance between veins equals the depth of vein placement within the leaf away from the evaporative surface. As presented here, only angiosperms maintain this anatomical optimum across all leaf thicknesses and different habitats, including sheltered environments where this optimization need not be required. Intriguingly, basal angiosperm lineages tend to be underinvested hydraulically; uniformly high optimization is derived independently in the magnoliids, monocots and core eudicots. Gymnosperms and ferns, including available fossils, are limited by their inability to produce high vein densities. The common association of ferns with shaded humid environments may, in part, be a direct evolutionary consequence of their inability to produce hydraulically optimized leaves. Some gymnosperms do approach optimal vein placement, but only by virtue of their ability to produce thick leaves most appropriate in environments requiring water conservation. Thus, this simple anatomical metric presents an important perspective on the evolution and phylogenetic distribution of plant ecologies and further evidence that the vegetative biology of flowering plants-not just their reproductive biology-is unique.

We compare the solutions of two systems of partial differential equations (PDEs), seen as two different interpretations of the same model which describes the formation of complex biological networks. Both approaches take into account the time evolution of the medium flowing through the network, and we compute the solution of an elliptic–parabolic PDE system for the conductivity vector m, the conductivity tensor C and the pressure p. We use finite differences schemes in a uniform Cartesian grid in a spatially two-dimensional setting to solve the two systems, where the parabolic equation is solved using a semi-implicit scheme in time. Since the conductivity vector and tensor also appear in the Poisson equation for the pressure p, the elliptic equation depends implicitly on time. For this reason, we compute the solution of three linear systems in the case of the conductivity vector m∈R2 and four linear systems in the case of the symmetric conductivity tensor C∈R2×2 at each time step. To accelerate the simulations, we make use of the Alternating Direction Implicit (ADI) method. The role of the parameters is important for obtaining detailed solutions. We provide numerous tests with various values of the parameters involved to determine the differences in the solutions of the two systems.

With the aim of recognizing and identifying both fertile and sterile specimens of Lauraceae from the Brazilian state of Bahia, we analyzed the leaf venation pattern of 56 species belonging to 14 genera (excluding Ocotea), 30 of them described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa. [ABSTRACT FROM AUTHOR]

In this research, the vein architecture of leaves belonging to 14 plant species having different morphological features were comparatively analyzed. Plant leaf samples were collected from various localities in Samsun province and were dried. The vein patterns were analyzed by applying a clearing and staining process to dried leaves. Significant differences were determined across the leaves of the studied species in terms of characters such as leaf perimeter and area, no of nodes and edges, total network length and total network area, mean length, mean width, mean 2D and 3D surface areas and mean volume of the edges. When the clearing and staining stages are applied carefully, the morphometric properties of the vascularization may provide reliable characters that will contribute to the research in many fields such as systematic, physiology and ecology. [ABSTRACT FROM AUTHOR]

Persea psammophila, a new species of Lauraceae collected near the border between the states of Bahia, municipality of Maiquinique, and Minas Gerais, municipality of Jordânia, Brazil, is described and illustrated. The new species belongs to Persea subg. Eriodaphne. It is distinguished from other Neotropical Persea species by the treelet habit in combination with sparsely pubescent twigs, elliptic to mainly obovate leaves, adaxially glabrous, abaxially sparsely pubescent and papillose, sparsely pubescent inflorescences, pubescent, relatively small flowers, and floral parts smaller than congeneric species in the Atlantic rainforest. Its putative relationships within the genus are discussed. Illustrations and comments on micromorphological and anatomical features of leaves of this new species are provided, comparing them to those of congeners. [ABSTRACT FROM AUTHOR]

With the aim of recognizing and identifying both fertile and sterile specimens of Ocotea from the Reserva Natural Vale, Linhares, we analyzed the leaf venation pattern of 31 species, 13 of them being described and illustrated for the first time. A dichotomous identification key was built from a matrix of 12 venation characters and 36 states, which allowed to distinguish the taxa. [ABSTRACT FROM AUTHOR]

Premise Clearing leaves is a highly useful practice for many taxonomic, ecological, physiological, and eco‐physiological aspects of research. Using traditional methods, the procedure for clearing a leaf (referred to as diaphanization) can take several days or even weeks. In our laboratory we developed a technique, originally used for dissociating wood, that yields excellent epidermal and leaf venation preparations clearly showing the details of epidermal cells, hydathodes, trichomes, leaf margins, and leaf venation, in a maximum of three days. Methods and Results A solution originally used to macerate wood (Franklin’s solution) was used to accelerate the process of clearing leaves. Using this approach, it is possible to obtain clear images of the leaf adaxial and abaxial epidermal surfaces and leaf venation. Our technique works with both fragile and sturdy leaves, as well as with thin roots and stems. A few examples are presented. Conclusions Franklin’s solution is very simple to prepare and easy to manipulate. This new technique has the advantage of separating the leaf epidermal layers and venations, which can then be clearly observed.

Premise Physiological processes may vary within leaf laminae; however, the accompanying heterogeneity in leaf venation is rarely investigated because its quantification can be time consuming. Here we introduce accelerated protocols using existing software to increase sample throughput and ask whether laminae venation varies among three crop types and four subspecies of Brassica rapa. Methods FAA (formaldehyde, glacial acetic acid, and ethanol)‐fixed samples were stored in ethanol. Without performing any additional clearing or staining, we tested two methods of image acquisition at three locations along the proximal‐distal axis of the laminae and estimated the patterns of venation using the program phenoVein. We developed and made available an R script to handle the phenoVein output and then analyzed our data using linear mixed‐effects models. Results Beyond fixation and storage, staining and clearing are not necessary to estimate leaf venation using phenoVein if the images are acquired using a stereomicroscope. All estimates of venation required some manual adjustment. We found a significant effect of location within the laminae for all aspects of venation. Discussion By removing the clearing and staining steps and utilizing the semi‐automated program phenoVein, we quickly and cheaply acquired leaf venation data. Venation may be an important target for crop breeding efforts, particularly if intralaminar variation correlates with variation in physiological processes, which remains an open question.

Variation in leaf veins along environmental gradients reflects an important adaptive strategy of plants to the external habitats, because of their crucial roles in maintaining leaf water status and photosynthetic capacity. However, most studies concentrate on a few species and their vein variation across horizontal spatial scale, we know little about how vein traits shift along the vertical scale, e.g., elevational gradient along a mountain, and how such patterns are shaped by plant types and environmental factors. Here, we aimed to investigate the variation in leaf vein traits (i.e., vein density, VD; vein thickness, VT; and vein volume per unit leaf area, VV) of 93 woody species distributed along an elevational gradient (1,374–3,375 m) in a temperate mountain in China. Our results showed that altitude-related trends differed between growth forms. Tree plants from higher altitudes had lower VD but higher VT and VV than those from lower altitude; however, the opposite tend was observed in VD of shrubs, and no significant altitudinal changes in their VT or VV. Plant phylogenetic information at the clade level rather than climate explained most of variation in three leaf vein traits (17.1–86.6% vs.

The sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae, Proconiini), a vector of the bacterium Xylella fastidiosa Wells et al. (Xanthomonadaceae) that causes citrus variegated chlorosis, has more than 30 reported host plant species. The fitness of a phytophagous insect is determined by the host plant suitability, plant resistance, and the natural enemies. The aim of this study was to: (1) identify plant species utilized as oviposition substrate by T. rubromarginata in the field; (2) establish the relationship between plants and clutch size; (3) establish the relationship among host plants, clutch size, and level of parasitism; and (4) establish variations in parasitoid composition and abundance in the various host plants. Egg masses of the sharpshooter were surveyed on plants reported as hosts, or those that were abundant in the study site. The number of eggs of the sharpshooter and emerged parasitoids were recorded for all the collected masses. We found egg masses of T. rubromarginata on 12 out of 21 plant species sampled. The size of the egg masses was greatly influenced by the type of leaf venation and to a lesser extent by the plant species. Parasitism rates were influenced by both leaf venation and host plant. Trichogrammatidae species were mostly associated with egg masses in plants with parallel‐veined leaves, whereas Mymaridae attacked masses laid in reticular‐veined leaves. The choice between a good host plant, but heavily attacked by parasitoids, and the host plants that are less suitable for nymphs but less frequently attacked by natural enemies, was a trade‐off for T. rubromarginata females to increase their fitness. We conclude that the host plant utilization by T. rubromarginata females in the field could be influenced by leaf structure and the strategy to avoid parasitism by selecting plants that were less attractive for parasitoids. [ABSTRACT FROM AUTHOR]

We analyzed vein and stomatal traits (vein density and vein volume per leaf area, stomatal density, stomatal pore length and pore index) and their relationships with other morphological traits [leaf area, leaf thickness and leaf mass per unit area (LMA)] of three co-occurring Mediterranean tree species with contrasting leaf habits [Quercus faginea Lam., Q. suber L. and Q. ilex L. subsp. ballota (Desf.) Samp.]. The results showed that leaf size, thickness and LMA varied among the species in parallel with the differences in leaf longevity. By contrast, the traits most related to water use showed inconsistent differences among the three species. Stomatal pore index was lowest in the species with intermediate leaf life span. The species with longest leaf longevity had highest vein density but minimum vein volume per area. Vein and stomatal traits also varied independently from other leaf traits within each species. The absence of association between LMA and vein volume suggests that a large LMA is the result of the accumulation of other tissues, and not necessarily veins. We concluded that in contrast with most economic leaf traits that tend to vary in parallel with leaf life span, traits related to water use varied inconsistently with leaf duration in the three species studied. Stomatal and vein traits, in addition, were not related to the maximum stomatal conductance of the different species. [ABSTRACT FROM AUTHOR]

Premise: Clearing leaves is a highly useful practice for many taxonomic, ecological, physiological, and eco‐physiological aspects of research. Using traditional methods, the procedure for clearing a leaf (referred to as diaphanization) can take several days or even weeks. In our laboratory we developed a technique, originally used for dissociating wood, that yields excellent epidermal and leaf venation preparations clearly showing the details of epidermal cells, hydathodes, trichomes, leaf margins, and leaf venation, in a maximum of three days. Methods and Results: A solution originally used to macerate wood (Franklin's solution) was used to accelerate the process of clearing leaves. Using this approach, it is possible to obtain clear images of the leaf adaxial and abaxial epidermal surfaces and leaf venation. Our technique works with both fragile and sturdy leaves, as well as with thin roots and stems. A few examples are presented. Conclusions: Franklin's solution is very simple to prepare and easy to manipulate. This new technique has the advantage of separating the leaf epidermal layers and venations, which can then be clearly observed. [ABSTRACT FROM AUTHOR]

Premise: Physiological processes may vary within leaf laminae; however, the accompanying heterogeneity in leaf venation is rarely investigated because its quantification can be time consuming. Here we introduce accelerated protocols using existing software to increase sample throughput and ask whether laminae venation varies among three crop types and four subspecies of Brassica rapa. Methods: FAA (formaldehyde, glacial acetic acid, and ethanol)‐fixed samples were stored in ethanol. Without performing any additional clearing or staining, we tested two methods of image acquisition at three locations along the proximal‐distal axis of the laminae and estimated the patterns of venation using the program phenoVein. We developed and made available an R script to handle the phenoVein output and then analyzed our data using linear mixed‐effects models. Results: Beyond fixation and storage, staining and clearing are not necessary to estimate leaf venation using phenoVein if the images are acquired using a stereomicroscope. All estimates of venation required some manual adjustment. We found a significant effect of location within the laminae for all aspects of venation. Discussion: By removing the clearing and staining steps and utilizing the semi‐automated program phenoVein, we quickly and cheaply acquired leaf venation data. Venation may be an important target for crop breeding efforts, particularly if intralaminar variation correlates with variation in physiological processes, which remains an open question. [ABSTRACT FROM AUTHOR]

Molecular phylogenetic results had shown that Tephroseris, a genus differentiated from its closest relatives by its pinnately veined leaves, also contains species with palmate leaf venation. This had led to the conclusion that leaf venation is a homoplasious character in the lineage containing Tephroseris. We here take a closer look at leaf venation in Tephroseris and other species of Asteraceae-Senecioneae. We found that leaf venation in Tephroseris is distinct from leaf venation in Jacobaea vulgaris and Senecio vulgaris, which both have pinnately veined leaves as typical for most species of their respective genera, and that description of the leaves of Tephroseris as pinnately veined is incorrect. Instead, leaf venation in Tephroseris is very similar to that of upper cauline leaves of Ligularia stenocephala, a species with clearly palmately veined basal and lower cauline leaves. Both L. stenocephala and Tephroseris are part of the Ligularia - Cremanthodium - Parasenecio (L - C - P) complex. We conclude that leaf venation in Tephroseris is best regarded as derived from palmate leaf venation found in the large majority of species in the L - C - P complex, and presents no morphological obstacle to the circumscription of the genus. [ABSTRACT FROM AUTHOR]

The purpose of this study is to identify plant species using leaf venation features. Leaf venation features were obtained through the extraction of leaf venation features. The leaf image segmentation was performed to obtain the binary image of the leaf venation which is then determined the branching point and ending point. From these points, the extraction of leaf venation feature was performed by calculating the value of straightness, a different angle, length ratio, scale projection, skeleton length, number of segments, total skeleton length, number of branching points and number of ending points. So that from the extraction of leaf venation features 19 features were obtained. Identification of plant species was carried out using Support Vector Machine (SVM) with RBF kernel. The learning model was built using 75% of the training data. The testing results using 25% of the data on the training model, obtained an accuracy of 82.67%, with an average of precision of 84% and recall of 83%. [ABSTRACT FROM AUTHOR]

Variation in leaf veins along environmental gradients reflects an important adaptive strategy of plants to the external habitats, because of their crucial roles in maintaining leaf water status and photosynthetic capacity. However, most studies concentrate on a few species and their vein variation across horizontal spatial scale, we know little about how vein traits shift along the vertical scale, e.g., elevational gradient along a mountain, and how such patterns are shaped by plant types and environmental factors. Here, we aimed to investigate the variation in leaf vein traits (i.e., vein density, VD; vein thickness, VT; and vein volume per unit leaf area, VV) of 93 woody species distributed along an elevational gradient (1,374–3,375 m) in a temperate mountain in China. Our results showed that altitude-related trends differed between growth forms. Tree plants from higher altitudes had lower VD but higher VT and VV than those from lower altitude; however, the opposite tend was observed in VD of shrubs, and no significant altitudinal changes in their VT or VV. Plant phylogenetic information at the clade level rather than climate explained most of variation in three leaf vein traits (17.1–86.6% vs. <0.011–6.3% explained variance), supporting the phylogenetic conservatism hypothesis for leaf vein traits. Moreover, the phylogenetic effects on vein traits differed between trees and shrubs, with the vein traits of trees being relatively more conserved. Together, our study provides new picture of leaf vein variation along the altitude, and highlights the importance of taking plant phylogeny into consideration when discussing trait variation from an ecological to a biogeographic scale. [ABSTRACT FROM AUTHOR]

We undertook a comparative study of the leaf venation characteristics of Dioscorea species from all seven sections distributed in China (33 species, 1 subspecies and 3 varieties). We established that leaf venation has a taxonomic significance in Dioscorea. The sections Combili, Opsophyton Lasiophyton and Shannicorea all show consistent acrodromous venation (a subtype of palmate venation), with Botryosicyos exhibiting consistent pinnate venation. However, sections Stenophora and Enantiophyllum show obvious intrasectional differences. For example, D. simulans and D. biformifolia of section Stenophora have acrodromously veined middle leaflets, whereas the side leaflets are pinnately veined; D. cirrhosa and D. cirrhosa var. cylindrica of section Enantiophyllum show dichotomous veinlets. Other species in the same section show either one-branched veinlets or multiple branched veinlets. In addition to the discrepancy in venation patterns, differences in many other important morphological characteristics and chemical components were also observed. Therefore, D. simulans and D. biformifolia can be reasonably excluded from section Stenophora, and section Illigerestrum can be rebuilt using these two species. In addition, D. cirrhosa and D. cirrhosa var. cylindrica should be removed from section Enantiophyllum and placed into another new section. D. simulans and D. biformifolia show pinnate venation, and the complexity of their leaf organization (with both simple and compound leaves) also points to variations between the pinnate and acrodromous veins in Dioscorea. The repeated presence of palmate and pinnate venation in multiple angiosperm clades also suggests that the formation and evolution of venation are likely the result of evolutionary adaptation to ecological environments.

The combined response of exclusion of solar ultraviolet radiation (UV-A+B and UV-B) and static magnetic field (SMF) pre-treatment of 200 mT for 1 h were studied on soybean (Glycine max) leaves using synchrotron imaging. The seeds of soybean with and without SMF pre-treatment were sown in nursery bags kept in iron meshes where UV-A+B (280–400 nm) and UV-B (280–315 nm) from solar radiation were filtered through a polyester filters. Two controls were planned, one with polythene filter controls (FC)- which allows all the UV (280–400 nm); the other control had no filter used (open control-OC). Midrib regions of the intact third trifoliate leaves were imaged using the phase-contrast imaging technique at BL-4, Indus-2 synchrotron radiation source. The solar UV exclusion results suggest that ambient UV caused a reduction in leaf growth which ultimately reduced the photosynthesis in soybean seedlings, while SMF treatment caused enhancement of leaf growth along with photosynthesis even under the presence of ambient UV-B stress. The width of midrib and second-order veins, length of the second-order veins, leaf vein density, and the density of third-order veins obtained from the quantitative image analysis showed an enhancement in the leaves of plants that emerged from SMF pre-treated seeds as compared to untreated ones grown in open control and filter control conditions (in the presence of ambient UV stress). SMF pre-treated seeds along with UV-A+B and UV-B exclusion also showed significant enhancements in leaf parameters as compared to the UV excluded untreated leaves. Our results suggested that SMF-pretreatment of seeds diminishes the ambient UV-induced adverse effects on soybean.

As a member of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION-related (CLE) peptide family, tracheary element differentiation inhibitory factor (TDIF) plays crucial roles in vascular meristem maintenance by promoting cell proliferation and inhibiting xylem cell differentiation. In Populus trichocarpa , six TDIF-encoding genes are all expressed in vascular tissues, and in Arabidopsis PtTDIFpro:GUS lines, the expression driven by PtTDIF promoters were predominantly detected in stem vascular bundles, initiating leaves and leaf veins. Although exogenous application of two poplar TDIF peptides did not evidently affect the shoot growth in vitro , overexpression of PtTDIF genes in hybrid poplar severely retarded the internodal elongation by upregulating the expression of GA2ox and GA20ox genes and thus decreasing the level of endogenous gibberellins (GAs), which phenotypic defect could be rescued by exogenously applied GA3. In addition, TDIF overexpression unexpectedly induced a more complex venation pattern in poplar leaves, which was underpinned by the elevated expression of WOX4 and WOX13 genes. Upon TDIF treatment, the DR5:GUS poplar leaves revealed a higher GUS activity and in TDIF -overexpressing leaves, the transcript abundances of several PIN-FORMED (PIN) genes, especially that of PIN1 , were increased, which implied an integration of TDIF and auxin in mediating this process. Collectively, data of this work presented novel activities of TDIF involved in internode elongation and leaf vein formation, thus revealing the divergent functions of TDIF in perennial tree species from those in annual herbaceous Arabidopsis. [ABSTRACT FROM AUTHOR]

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Premise: The proportion of woody dicots with toothed leaves increases toward colder regions, a relationship used to reconstruct past mean annual temperatures. Recent hypotheses explaining this relationship are that (1) leaves in colder regions are thinner, requiring thick veins for support and water supply, with the resulting craspedodromous venation leading to marginal teeth (support–supply hypothesis) or that (2) teeth are associated with the packing of leaf primordia in winter buds (bud‐packing hypothesis). Methods: We addressed these hypotheses by examining leaf thickness, number of primordia in buds, growing season length (mean annual temperature, MAT), and other traits in 151 deciduous woody species using georeferenced occurrences and a Bayesian model controlling for phylogeny. We excluded evergreen species because longer leaf life spans correlate with higher leaf mass per area, precluding the detection of independent effects of leaf thickness on leaf‐margin type. Results: The best model predicted toothed leaves with 94% accuracy, with growing season length the strongest predictor. Neither leaf thickness nor number of leaves preformed in buds significantly influenced margin type, rejecting the support–supply and bud‐packing hypotheses. Conclusions: A direct selective benefit of leaf teeth via a carbon gain early in the spring as proposed by Royer and Wilf (2006) would match the strong correlation between toothed species occurrence and short growing season found here using Bayesian hierarchical models. Efforts should be directed to physiological work quantifying seasonal photosynthate production in toothed and nontoothed leaves. [ABSTRACT FROM AUTHOR]

Premise of research. Although the Nymphaeaceae are an ancient angiosperm family, fossil leaves with nymphaeacean affinities from the Paleogene have nearly always been assigned to modern genera. Yet during the diversification of this group, it is extremely likely that transitional forms in this family evolved since its origin over 100 million years ago and should show up in the fossil record. Here, we describe an extinct genus of nymphaeacean leaf with transitional characters from the Eocene Lake Messel locality, which is, according to phylogenetic analysis, a member of the main Nymphaeaceae clade excluding Nuphar. Methodology. Over 39 fossil leaves from the Messel Pit near Darmstadt, Germany, were studied, coded for 40 of 55 morphological and leaf architecture characters, and analyzed phylogenetically. Analyses were run with PAUP* of the Messel leaf morphotype combined with living taxa and then together with previously described fossil Nymphaeales. Pivotal results. Inclusion of the Messel leaf with living taxa results in three trees with similar topology except for the relationship within Nuphar. Bootstrap data strongly support inclusion of the Messel leaf in the order Nymphaeales and the family Nymphaeaceae. In analyses with only living taxa, the Messel leaf places beyond Nuphar within the remaining Nymphaeaceae. In analyses with living and other fossil taxa, it places at the base of the Nuphar clade. Based on its suite of characters, the Messel leaf is recognized here as an intermediate between existing genera and described as a new extinct genus and species. Conclusions. The Eocene water lily from Messel is described here as a new genus and species, Nuphaea engelhardtii Gee and David W. Taylor gen. et sp. nov., and is represented by leaves with characters that are transitional to those of modern Nuphar , Nymphaea , and other Nymphaeaceae. This study offers new evidence of greater biodiversity in Nymphaeaceae in the Cenozoic. [ABSTRACT FROM AUTHOR]