Leaf Morphotypes Research Articles

Leaf polymorphism of beeches from the Jura (France) in the late Pliocene (Piacenzian): contribution to taxonomy in palaeobotany

Fossilized beech leaves were extracted from nodules in the Bletterans plateau (Jura, France) dating back to the Late Pliocene (Piacenzian, -2.7 Ma). During this period, seasonality was much less pronounced than it is today. A warm climate allowed the development of deciduous tree vegetation, comprising a mixture of tropical, subtropical, and temperate forests without modern analogues, including the presence of Fagus and Quercus. Various qualitative and quantitative morphological traits were studied, as well as comparisons with leaves from fossil species such as F. menzelii and F. kraeuselii,and leaves from present-day species like F. grandifolia and F. sylvatica. The most discriminative features include the basal angle, the angle between primary vein and secondary veins, the angle between primary vein and tertiary veins, and the density of tertiary veins. Three distinct groups stand out, referred to as morphotypes indicating environmental variations rather than genetic groups. Leaves of F. sylvatica separate into two distinct morphotypes, whereas the American species F. grandifolia, and the European species F. kraeuselii and F. menzelii, form a third morphotype. The Bletterans samples are close to these three morphotypes. These morphological correspondences do not allow associating a species to the jurassian samples, but they support the existence of leaf morphotypes acclimated to fluctuating environmental conditions.

Ecophysiological and nutritional characterisation of two morphotypes of Cakile maritima subsp. maritima Scop. from Puglia region, Southern Italy.

Cakile maritima subsp. maritima Scop. (sea rocket) is a succulent halophyte with significant potential as a nutritious food source, being rich in essential nutrients such as vitamins, minerals, and antioxidants. This annual species exhibits two distinct leaf morphotypes: entire lamina (EL) and pinnatifid lamina (PL). Our understanding of their ecophysiological and nutritional profiles is still limited. The present study investigated the wild EL and PL sea rocket plants from southern Italy during their vegetative stage. The bio-morphological traits (leaf mass area-LMA, dry matter and chlorophyll concentrations), main inorganic ions, key antioxidants (carotenoids, anthocyanins, phenols, flavonoids, glucosinolates, vitamin C as ascorbic and dehydroascorbic acid), and antioxidant activity (by FRAP, DPPH, ABTS assays) were analyzed. Additionally, photosynthetic gas exchange and chlorophyll fluorescence were measured. PL plants showed thicker leaves (higher LMA) and greater accumulation of photo-protective pigments (carotenoids and anthocyanins), despite similar chlorophyll levels. The PL plants also demonstrated higher photosynthetic activity, transpiration rates, and stomatal conductance, with reduced non-photochemical quenching. The EL morphotype had higher cation (K, Mg, Ca, Na) and vitamin C (135.3 mg 100 g-1 FW) concentrations, while no significant disparities were observed between the morphotypes in phenolic concentration (208.5 mg g.a.e. 100 g-1 FW), flavonoids (71.5 mg q.e. 100 g-1 FW), or glucosinolates (61 mg g-1 FW). Interestingly, while the EL type had higher vitamin C, the PL morphotype showed superior antioxidant activity (FRAP, DPPH) and seems to be better adapted to water/nutrient scarcity typical of southern Italy. Both morphotypes offer potential as high-nutritional foods, however, future research should investigate the genotype-specific production of antioxidant compounds in EL and PL plants in response to environmental stresses, including salinity for potential exploitation as a new crop.

Hairy roots biochemical characteristics of vegetable pea’s morphotype with modified leaf

BACKGROUND: In the literature, data on the successful production of high-protein pea root cultures with mutant alleles tl and af tl and their biochemical characteristics are not presented. AIM: The aim of this study is the biochemical characteristic of the obtained transformed cultures of mutant pea lines with a modified leaf morphotype was. Rol genes clarification of transformed pea mutant lines by wild strains of Agrobacterium rhizogenes and amino acid analysis of the total protein of the obtained roots cultures were objectives of the research. MATERIALS AND METHODS: Total DNA has been isolated from pea mutant root cultures. The studies were carried out on the equipment of the thermal cycler Tertsik of the company DNA-Technology (Russia). Amplicons were detected by electrophoresis in a 2% agarose gel. The gel was visualized and photographed under ultraviolet light (λ = 312 nm). The quantitative and qualitative amino acid composition of root cultures was determined by ion exchange chromatography on the amino acid analyzer AAA-339 (Microtechna, Czech Republic). RESULTS: PCR analysis revealed the absence of agrobacterial contamination in the transformed cultures and their stable growth on liquid and agar hormone-free media for 5 years. PCR assay showed the presence of rol C and D genes in culture with the tltl genotype and four rol genes A, B, C, and D in culture with the afaftltl genotype. A differentiated content of a number of amino acids in the biomass of transformed cultures was found depending on the genotype of the culture and the insertion of rol genes. Seven essential amino acids were identified in both cultures. CONCLUSIONS: Tryptophan turned out to be the limiting essential amino acid for both cultures. In terms of the sum of essential, ketogenic and sulfur-containing amino acids, the culture with the rol genes A, B, C, and D turned out to be the richest and most balanced.

A contribution to the variability of Prunus spinosa L. in the vicinity of the mediaeval Castle Kolno, S-W Poland

The variability of fruit stone characteristics of medieval fossil forms and modern ones was analysed in a small Prunus spinosa (blackthorn) population in the vicinity of Castle Kolno near Stare Kolnie in Opole Province. A modern putative hybrid resulting from natural crossing with cultivated plums was discovered, corresponding to some fossil morphotypes. The analysis of the correlations of features indicated developmental relationships between them. The pattern of variability of the examined stones in the ordination space confirmed the development of the Prunus spinosa-Prunus domestica complex as an element of a dynamic syngameon. The population also showed variations in leaf morphotypes, which may be used in taxonomic analysis.

An Eocene leaf flora from the northern Peruvian Andes

The fossil forest known as El Bosque Petrificado Piedra Chamana lies in close proximity to the village of Sexi in the Department of Cajamarca in northern Peru. The forest was deposited in either a lahar or pyroclastic flow, and ashfall deposits, as mineralized wood and leaf impressions 39 million years ago (late Middle Eocene). More than 30 types of non-monocot angiosperms have been described from the fossil wood, which is densely embedded in rock outcrops, scattered across the ground, and occasionally found in situ. Anatomical characteristics and identifications of the woods suggest a seasonally flooded lowland tropical forest with a dry period. This site also preserves a small leaf flora which has not received a full treatment in earlier works and is the focus of the present study. The leaves are described in detail using standard leaf architecture terminology. The flora has 31 non-monocot leaf morphotypes. The presence of more than 30 morphotypes suggests high diversity based on having only ∼210 non-monocot leaf specimens. The leaf collection also includes ∼10 monocot specimens. One of the leaf morphotypes shows similarities to the extant mangrove genus Avicennia, possibly confirming one of the fossil wood identifications. Most of the leaves are incomplete, but when the margin is preserved, it is untoothed. The lack of teeth indicates a warm, tropical climate (estimated mean annual temperature of >25 °C based on leaf margin analysis). Leaves in the collection are small with 28 of 31 morphotypes inferred as microphyll or notophyll in laminar size, providing support for the seasonal dryness indicated by the fossil woods. Despite the small size of the collection, this leaf flora is important to document as there are few Eocene plant macrofossil localities in Peru; it provides some insight into the Cenozoic forests in this understudied region.

The effect of a vegetation period on protein percentage in seed of the pea collection samples

The purpose of the study was to identify the effect of the length of a vegetation period of collection samples on protein percentage in pea seed. The study was carried out in the southern part of the Rostov region on the fields of the FSBSI «ARC «Donskoy» in 2017–2020. The objects of the study were 100 collection pea samples from the N. I. Vavilov ARIPGR (VIR), including 53 leafless samples and 47 leafy ones. The longest vegetation period on average for the collection (93.8 days) was identified in 2017. The intervarietal variability of this trait, expressed by a variation coefficient, this year was 5.5 % with a minimum value of 63 days and a maximum of 101 days. In the group of varieties of the leafless type, the intervarietal variability was 6.4 % (min. 63 days; max. 100 days), in the leafy group it was 4.2 % (min. 80 days; max. 101 days). In other years, there was a reduction of a vegetation period and a decrease in its intervarietal variability due to unfavorable weather conditions in the form of a lack and shortage of precipitation against the background of elevated and high air temperatures. But they also led to the maximum accumulation of protein in seeds of collection samples, thereby showing the greatest intervarietal variability of this indicator. The calculation of the correlation coefficient showed the absence of a correlation dependence of protein percentage on length of vegetation, both on average for the collection (r = 0.03+0.10) and for the groups of leafless (r = 0.08+0.14) and foliate (r = 0.05+0.15) leaf morphotypes. The construction of graphs with errors for groups of leafy morphotypes revealed samples with a protein percentage of more than 25.0 %. In the group of the leafless morphotype, they had a vegetation period of 78–80 and 83–85 days, and in the group of the leafy morphotype, it was 77–79 days on average over the years of study.

Leaf heteroblasty and morphotypes of Acer monspessulanum (Djurdjura, Algeria) as revealed by traditional and geometric morphometrics

The genus Acer which is largely distributed in the Northern hemisphere is represented in Algeria by four species of which Acer monspessulanum is the most common. These four species and their putative hybrids are coexisting in many parts of their Algerian distribution range but their leaf morphology has not been the subject of quantitative analyses despite the interest of such kind of data in taxon delineation particularly in the case of interspecific hybridization. The present work is the first step towards a quantitative analysis of leaf morphology in Acer species in Algeria. We presently relied on traditional and geometric morphometrics methods in the study of Acer monspessulanum subsp. monspessulanum leaf morphology in two sites of the Djurdjura Mountain with consideration of tree and within-shoot effects. The results showed congruence between the two methods which both highlighted the presence of a marked heteroblasty. Basal leaves are twice as large as apical ones for all measured leaf features. The petiole is longer than the blade in basal leaves and inversely in apical ones. The median leaves have intermediate values. The results revealed also the coexistence of two contrasted leaf morphotypes on distinct trees of both sites.

Characteristics of heteroblasty in Hladnikia pastinacifolia (Apiaceae), a rare endemic from Slovenia

Hladnikia pastinacifolia, the most prominent endemic plant species in Slovenia, is rare and protected because it is a stenoendemic and paleoendemic species restricted to area of Trnovski gozd (W Slovenia). However, this species can be found in various habitats. The disparity between the non-specific habitat preference of the species and its rarity has not been sufficiently explained. Here we focus on the functional morphological features that are most indicative for the ecology of plant species: the anatomical and morphological characteristics of leaves. Hladnikia pastinacifolia exhibits heterophylly during ontogeny (heteroblasty). We aimed to describe and compare the anatomical characteristics of three H. pastinacifolia leaf morphotypes among them and in relation to various habitats. Therefore, we compared leaf functional features that are indicative for the ecology of plant species: the thickness of the leaf lamina, the spongy and palisade parenchyma, the thickness of the upper and lower epidermis and the number of leaf stomata in the upper and lower epidermis. These measurements were further used to calculate the ratio between the spongy and palisade parenchyma, leaf stomata index and the density of leaf stomata. We determined that the H. pastinacifolia heteroblasty belongs to the Apium-type. Results showed that the five-pinnate leaves were the most distinct type, being the thickest, with the highest numbers of stomata abaxially. When compared among habitats, leaves from the scree habitat were the thickest according to all the tissue layers studied. The indices calculated were less useful for the distinction between leaf types and habitats.

Paleocene high-latitude leaf flora of Antarctica Part 1: entire-margined angiosperms

Paleocene leaf floras are rare in high latitudes of the Southern Hemisphere, where studies have shown higher taxonomic diversity compared to Northern Hemisphere equivalents. The floras provide valuable insights into biodiversity and forest communities during the Paleocene. The Antarctic Peninsula hosts a wealth of Paleocene–Eocene floras which have been used to interpret climates before, during and after one of the most abrupt and transient warming events known from the geological record. The best-preserved and most diverse Paleocene macrofossils from this region come from the Cross Valley Formation, Seymour Island Group, which have previously provided evidence for warm temperate climates prior to the PETM. Here we present the taxonomy of leaf impressions from the Paleocene Cross Valley Flora for one species and ten new leaf morphotypes of entire-margined angiosperms. The new morphotypes provide evidence of an increased angiosperm diversity within cool-temperate Gondwanan forest inhabiting the east side of the Antarctic Peninsula, which contrasts with a lower floral diversity on the west side of the Peninsula during the late Paleocene.

Revisiting the Late Cretaceous Parataxodium wigginsii flora from the North Slope of Alaska, a high-latitude temperate forest

Reinvestigation of a Late Cretaceous plant assemblage from along the Colville River on the North Slope of Alaska reveals both that the flora is far more diverse than previously suspected, and that many specimens are anatomically preserved. The flora includes one moss, an osmundaceous fern, one species of Ginkgo, the putative conifer leaf Pityophyllum, five species of cupressaceous conifers, five dicot leaf morphotypes, and one monocot. The cupressaceous remains heretofore have been interpreted as a single taxodioid/sequoioid conifer species, Parataxodium wigginsii Arnold and Lowther. However, reexamination of the fossils reveals five different morphologies of cupressaceous ovuliferous cones, and a wide range of intergrading leafy shoot morphologies. Peel sections show excellent internal anatomy for many of the cupressaceous conifer organs, as well the moss. These fossils characterize a high-latitude deciduous flora dominated by cupressoid conifer trees, with less common dicot and Ginkgo trees, and with ground cover that includes osmundaceous ferns, monocots, and dicranalean mosses. The increased diversity of disarticulated plant parts in the assemblage demonstrates that Parataxodium wigginsii is not nearly as well understood as widely believed, and that the genus and species concepts as currently defined may be based on organs from several cupressaceous conifers. This assemblage is an outstanding example of an unusual Late Cretaceous, high-latitude, Northern Hemisphere, mixed dicot-coniferous, cool temperate, deciduous forest that existed in total darkness for a significant period each year.

Delimiting a constellation: integrative taxonomy of a star-shaped Hydrocotyle species complex (Araliaceae) from the Brazilian Atlantic forest

Species delimitation must overcome the inconsistency among the different delimitation criteria to maintain species as reliable units for biological research and conservation. The general lineage species (GLS) concept embraces different methods of species delimitation and thus provides an integrative framework for taxonomy. The Hydrocotyle stella complex contains six morphotypes that occur along mountain ranges within the Brazilian Atlantic forest, possibly representing undescribed species. In this study, we adopted the GLS concept to assess whether H. stella would be a single species or not, in which we considered genetic structure and morphological discontinuity as evidences for species delimitation. We applied ISSR-based population genetics and morphometrics to 12 populations of H. stella, representing all morphotypes across their main geographical range. Population genetics revealed three genetically structured groups (ΦST > 0.22), each associated with different mountain range regions. Morphometrics indicated significant (p < 0.001) morphological divergence among genetically structured groups, but not for all of the traditional leaf morphotypes. Based on congruency between genetic structure and morphological discontinuity, we recognized three species within the complex, H. alpina, H. palacea, and H. quinqueradiata, and provided their due taxonomic treatment.

The Zanclean palaeofloras around the Mont-Dore strato-volcano: A window into upper Neogene vegetation and environments in the Massif Central (Puy de Dome, France)

New Pliocene macrofloras and microfloras perfectly preserved from the Mont-Dore (Puy-de-Dôme, Massif central, France) have been reinvestigated. Samples come from different stratigraphical levels collected from three localities, Lac Chambon, La Gratade and Pont de Chocol. The 40Ar/39Ar radiometric datings bracketing the Chambon Lake and La Gratade fossil-bearing horizons give 4.46±0.05Ma and 3.94±0.04Ma, respectively, representative of the Zanclean Stage (= Brunssumian B and C), a period of the early Pliocene (5.32 to 3.6Ma), much older than previously thought (i.e., Piacenzian). Pont de Chocol is considered to be close biostratigraphically, or even identical in age to La Gratade. Detailed morphological evaluation of leaf morphotypes completed with pollen analysis contributed to the better taxonomic knowledge of these palaeofloras. The overview focuses on floristic and phytostratigraphical characteristics of the defined stratigraphical units and their dating and correlation with previously defined palaeofloristic units of the Massif central. The study provides detailed identifications of plants representing 11 gymnosperms among which Pinaceae (pollen and winged seeds), Cupressaceae including “Taxodioid” pollen grains and Sciadopitaceae families (only pollen). Besides, different angiosperm trees and shrubs have been determined from both micro- and macro-remains. Fagaceae is the most diversified with several foliage of beech and deciduous oaks, while diversified Juglandaceae contribute mainly as abundant leaf remains of Carya, Pterocarya and Juglans; Ulmaceae with numerous leave of two Zelkova species, and also Ulmus. Various other deciduous dicotyledonous such as Alnus, Betula, Carpinus, Populus, Acer laetum and A. interrigenum are well documented. Leguminosae are recorded by a small number of leaflet imprints. Evergreen shrubs of Buxaceae (Buxus pliocenica) are scarce. All these taxa contribute to a rich biodiversity of these Pliocene assemblages. All three sites point towards riverine forest habitats dominated by hygrophilic diversified woody plants while in the surrounding plains and slopes the thermophilic elements were scarce and mesophilic taxa abundant as temperate elements. This vegetation can be compared with mixed mesophytic forests depicting a climate cooling during the two considered periods (ca. 4.46 and 3.95Ma).

The Kanaka Creek fossil flora (Huntingdon Formation), British Columbia, Canada — paleoenvironment and evidence for Paleocene age using palynology and macroflora

Paleogene sediments of the Huntingdon Formation, a correlative to the Chuckanut Formation of neighbouring Washington State, USA, are exposed in the Greater Vancouver area, British Columbia, Canada. Palynology and plant macrofossils suggest the Kanaka Creek section is Paleocene rather than Eocene in age. Detrital zircon dating is less decisive, yet indicates the Kanaka rocks are no older than Maastrichtian. Analyses of plant macro- and micro-fossils suggest an early to middle Paleocene age for the Kanaka fossil flora. Paleocene indicators include macrofossils such as Platanus bella, Archeampelos, Hamamelites inequalis, and Ditaxocladus, and pollen taxa such as Paraalnipollenites, Triporopollenites mullensis, and Duplopollis. Paleogene taxa such as Woodwardia maxonii, Macclintockia, and Glyptostrobus dominate the flora. Fungal spores including the Late Cretaceous Pesavis parva and the Paleogene Pesavis tagluensis are notable age indicators. Physiognomy of 41 angiosperm leaf morphotypes from Kanaka Creek yields mean annual temperatures in the microthermal to lower mesothermal range (11.2 ± 4.3 to 14.6 ± 2.7 °C from leaf margin analysis; 14.8 ± 2.1 °C from Climate Leaf Analysis Multivariate Program), with mild winters (cold month mean temperature 3.9 ± 3.4 °C). Paleoclimate was cooler than the upper Paleocene and Eocene members of the Chuckanut Formation. Mean annual precipitation is estimated at ∼140 cm with large uncertainties. The Kanaka paleoflora is reconstructed as a mixed conifer–broadleaf forest, sharing common taxa with other western North American Paleocene floras and growing in a temperate moist climate. Kanaka Creek is a rare coastal Paleocene plant locality that provides new insights into coastal vegetation and climate prior to the Paleocene–Eocene Thermal Maximum.

Morphological and anatomical plasticity of a rare amphibious species of Eriocaulaceae (Poales, Monocotyledons)

Phenotypic plasticity is common in aquatic monocots, but is sometimes mistaken with heteroblasty. In Eriocaulaceae, aquatic and amphibious species may present interesting adaptive morphological features. However, Paepalanthus saxicola var. pilosus is unusual by having two leaf morphotypes and scapes that can be partially submerged or completely exposed. This taxon also presents an uncertain identity due to its incomplete morphological description. Here, we studied the morphology and anatomy of both leaf morphotypes and of scapes of P. saxicola var. pilosus to understand if the morphological differences in leaves correspond to phenotypic plasticity or heteroblasty; and the ecological and systematic significance of its leaves and scapes. Besides, we describe its morphology to evaluate its identity. The short curved leaves show supporting tissue and three vascular bundles, while the long filiform ones lack supporting tissue and have a single vascular bundle. All specimens share anatomical characteristics of scape. We raised this taxon to the species level, giving it a replacing name, Paepalanthus amphibius. We observed that P. amphibius is the first confirmed report of heterophylly in Eriocaulaceae. The anatomy of its short leaves and scapes reflects adaptations to a xeric environment, while the anatomy of the long leaves shows characteristics adapted to an aquatic habit. Possibly, such degree of plasticity is underreported in the family, so we stress the importance of seasonal studies to understand the morphology and taxonomy of the amphibious species.

The Cenozoic leaf morphotypes and palaeoclimate interpretation from the Doi Ton Formation, Mae Sot District, Tak Province, western Thailand

The Cenozoic palaeovegetation and palaeoclimate of Doi Ton, western Thailand, megaflora are reconstructed based on physiognomic climate analysis, including Leaf Margin Analysis (LMA), Leaf Area Analysis (LAA), Leaf Size Index (LSI), Climate Leaf Analysis Multivariate Program (CLAMP), and systematic descriptions of each leaf morphotype. The leaf fossils were divided into 23 dicotyledonous leaf morphotypes and two unknown leaf morphotypes. The mean annual temperature results from LMA indicate 32.3 ± 1.17 °C and CLAMP shows 21.2°C. CLAMP also provides temperature data of a warm month mean temperature (WMMT) of 27.4 °C and a CMMT of 14.2 °C, which is similar to the present climate. The mean annual precipitation is estimated by LAA to be ~ 125 cm. CLAMP suggests precipitation in the 11 months of growing period was 154.9 cm with the three wettest months having precipitation of 73 cm, widely contrasting with 15.5 cm for the three driest months. The precipitation shows the signal of the monsoon effect. The temperature, precipitation, and LSI mirrored the vegetation of the contemporary Doi Ton area which is a semi-evergreen forest in the tropical zone. The palaeoclimatic parameters of Doi Ton are in good agreement with those of south China and northwestIndia from the Eocene period and the present-day Mae Sot area. Moreover, the Doi Ton flora also closely matches the humid subtropical modern vegetation of south China. Palaeoclimate and vegetation analysis support an Eocene age estimate for the Doi Ton Formation however further independent age estimates are required to test this working hypothesis.

Ecological dynamic equilibrium in an early Miocene (21.73 Ma) forest, Ethiopia

Miocene paleoecology of East Africa has implications for human origins and understanding the vicariant legacy forests found today on either side of the East African Rift. Fossil leaves preserved in 21.73 million year old lacustrine sediments from the Mush Valley, Ethiopia, provide a unique opportunity to investigate forest composition and dominance-diversity patterns at an ecological scale. We classified and analyzed 2427 leaves in total from two to three quarries within each of six stratigraphic levels, spanning 7 m of section; we estimate each quarry census represents one to three centuries, and 50–60 kyrs separate the oldest and youngest levels. Pollen, phytolith, and compound-specific organic geochemical data were also collected in a detailed stratigraphic context to provide independent, integrated lines of evidence for landscape evolution and lacustrine paleoecology of the system that preserves the macrofossils. Forty-nine leaf morphotypes were documented, and Legume 1 dominated all samples. Nonmetric multidimensional scaling, Jaccard similarity analyses, and diversity and evenness indices demonstrate a degree of change comparable to community ecology dynamics, likely illustrating a dynamic stable state in forest vegetation surrounding the lake. Taxonomic assessments of leaves, phytoliths, and pollen are consistent with a closed canopy forest with limited palm diversity. A high abundance of des-A ring triterpenoid molecules (diagenetic products formed by microbial degradation under anoxic conditions) and very negative δ13C values (<−45‰) of several hopanoid compounds point to anoxic conditions at the lake bottom, consistent with exquisite fossil preservation. The proportion of mid-chain n-alkanes is low, signifying relatively few submerged plants, but increases up-section, which signals shallowing of the paleolake. The Mush Valley locality is unique in Africa with regard to its very early Miocene age and the abundance and quality of organic remains. This densely forested landscape in an upland volcanic region of the Ethiopian Plateau showed resilience amid volcanic eruptions and had botanical affinities with species found today in West, Central, and eastern Africa.

An Extinct Transitional Leaf Genus of Nymphaeaceae from the Eocene Lake at Messel, Germany: Nuphaea engelhardtii Gee et David W. Taylor gen. et sp. nov.

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.

Phytolith analysis of the main species of Distichlis sp. (Chloridoideae: Poaceae) distributed in South America

The Saltgrasses are pioneer plants in the early stages of succession in saline soils and constitute particular zonal communities of low species variability. Phytolith assemblage analysis of these species allows a community type to be characterized that consists mainly of species with well-defined environmental adaptations, which are significant because of their paleoecological importance. The aim of the present study is to characterize phytolith assemblages of Distichlis species in South America, emphasizing their leaf morphotypes. Four Distichlis species, mainly of South American distribution, and four chloridoids species from different clades of the subfamily (Lycurus, Eragrostis, Muhlenbergia and Sporobolus) were selected for this study. The phytoliths were obtained following Labouriau's calcination technique. Quantitative analysis of the morphotype abundance in the phytolith assemblages studied allowed the three main groups to be distinguished, with the common presence of multicellular phytoliths with long, short, bulliform and subepidermal silicified cells, as well as unicellular phytoliths, such as short narrow saddle, prickles and hairs, polyhedral and long elongate types. Conversely, the exclusive presence of horned towers, short truncated cones, circular/ovoid, papillae trichome, silicified microhairs, and isolated and articulated irregular epidermal cell phytoliths in Monanthochloinae clade species distinguishes them from the Muhlenbergiinae clade species with square/rectangular and subrectangular saddles and acute dumbbells. Eragrostis and Sporobolus species have shown some particular morphotypes (such as hairs with cushions, long truncate cones, dumbbell and dumbbell/saddle). The results not only allowed us to identify the Distichlis species, but also to distinguish them from other grasses, including those in their subfamily; and represent a potential tool to identified halophytes environments outside New World saltgrasses.

Assessing modern arboreal phytolith sensitivity to vegetation variations in temperate forest regions

To assess the reliability of arboreal phytoliths for differentiating vegetation types in temperate forest regions, we systematically analysed arboreal leaf phytoliths from 72 arboreal plants and 49 modern soils from three forest types in northeast China. The arboreal leaf phytolith production and morphotypes were highly variable between species. The arboreal leaf phytolith assemblages could clearly distinguish between broadleaf and coniferous species, but they were much less successful in differentiating broadleaved trees into subtaxa. Coniferous leaf morphotypes were successfully used to differentiate coniferous trees into families and subtaxa, especially in the Pinaceae. Two diagnostic broadleaved and six coniferous phytolith morphotypes were recognized within the modern soil beneath forest ecosystems. These arboreal phytoliths comprised up to 10–15% of the total soil phytoliths, and were dominated by coniferous types. Arboreal phytolith concentrations and phytolith assemblages in the soils fluctuated substantially amongst the three forest types. Soil arboreal phytolith assemblages were successfully used to differentiate samples from Larix mixed forest, broadleaf forest and Pinus koraiensis mixed forest. In addition, the arboreal index quantitatively distinguished the three forest types, with B/BE values &lt;0.4 for Larix mixed forest samples, values from 0.4 to 0.6 for broadleaf forest samples, and values from 0.6 to 0.9 for P. koraiensis mixed forest. Thus, our surface soil arboreal phytolith assemblages and arboreal index are a useful reference for differentiating forest ecotypes, and they also provide reliable analogues for arboreal phytoliths from palaeoecological contexts in temperate forest regions.

Middle to Late Paleocene Leguminosae fruits and leaves from Colombia

Leguminosae are one of the most diverse flowering-plant groups today, but the evolutionary history of the family remains obscure because of the scarce early fossil record, particularly from lowland tropics. Here, we report ~500 compression or impression specimens with distinctive legume features collected from the Cerrejón and Bogotá Formations, Middle to Late Paleocene of Colombia. The specimens were segregated into eight fruit and six leaf morphotypes. Two bipinnate leaf morphotypes are confidently placed in the Caesalpinioideae and are the earliest record of this subfamily. Two of the fruit morphotypes are placed in the Detarioideae and Dialioideae. All other fruit and leaf morphotypes show similarities with more than one subfamily or their affinities remain uncertain. The abundant fossil fruits and leaves described here show that Leguminosae was the most important component of the earliest rainforests in northern South America c. 60–58 million years ago.