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Fil: Carrizo, Martin Alejandro. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

A study on the leaf cuticle ultrastructures of Baiera furcata from the Lower Cretaceous Huolinhe Formation in East Inner Mongolia, Northeast China, was conducted with transmission electron microscopy (TEM) and elements analysis by Energy Dispersive Spectroscopy (EDS). TEM observation revealed the ultrastructural details from ordinary epidermal cells for both upper and lower cuticles, and stomatal apparatus, which were all made with A2 (granular) and B1 (fibrilous) layers. Additionally, well-preserved cell remnants were also observed. Comparisons with other cuticles of the Ginkgoales were made using statistical measurements and evaluations of some potential Order characteristics, and genus–species characteristics were also emphasized. Two potential ultrastructural groups can be recognized: Baiera–Sphenobaiera and Ginkgo–Ginkgoites–Pseudotorellia. This is reinforced by EDS element analysis, whereby ratios could also be compared with another closely related Ginkgoalean taxon Sphenobaiera huangii. The paleoenvironment significances is discussed, and it seems to support the TEM and EDS results. It indicates a signature in the cuticle fine details of Sphenobaiera, which has experienced a putatively warmer paleoenvironment than that of Baiera.

Although the cuticle is a very thin layer of a few micrometers, it is one of the main remains found among fossil plants. Apparently very fragile, ultrathin cuticle sections of few dozen nanometers thick are studied by using TEM studies and statistical measurements. The ultrastructure details yielded are of significance not only for taxonomy, but also for paleoenvironment and evolution of fossil plant. After an historical introduction and a review of the methods to obtain and observe the ultrathin sections, although data are still not enough numerous, detailed information and interesting facts of cuticle ultrastructure emerge from the studied plant groups. This paper gives a review of the main results of transmission electron microscopy -TEM- of fossil plant cuticles since the pioneering study 33 years ago.

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International audience; The Cheirolepidiaceous conifer Suturovagina intermedia Chow et Tsao is reported from the Lower Cretaceous of Wangqing, Jilin Province in northeastern China, and its leaf cuticles were studied in detail using scanning and transmission electron microscopies and EDS. The data obtained were compared with those of the previous study on the same species from the Lower Cretaceous of the type locality Nanjing, Jiangsu Province in eastern China. Despite the general similarity in gross morphology and leaf cuticular structure, there are a number of differences in leaf cuticular ultrastructure and element composition (EDS data) between specimens from the two localities. Among them, 14 differences are potential tax- onomical characters. Of them, 7 might be of importance at the species/genus level, and 7 are possible characters at the family level. There are also 23 differences, i.e., 7 cuticle ultrastructural characters of ordinary epidermal cell cuticles and 5 subsidiary cell cuticles, plus 11 EDS ratios of cuticles, believed to be of ecological signi␣cances. This paper presents the ␣rst case to make comparative palaeoenvironmental analyses based on leaf cuticle ultrastructure and element composition of the same taxon from different areas. It shows that Suturovagina intermedia was an inhabitant of a lower xerothermic environment in Wangqing, instead of being a higher xerothermic environment, such as in the type locality Nanjing. The conclusion obtained is well-supported by the evidence of the element composition (EDX data) of the matrix and the associated biotic composition of the fossil-bearing beds from the two localities. It is the ␣rst attempt to search for the environmental footprint in fossil plant cuticles based on their element composition.

Clathropteris was a typical dipterid fern with well documented fossil record and was widely dispersed during the Mesozoic; however, our knowledge of fertile structures including in situ spores for this genus is still very limited. Here we report well-preserved compression specimens of Clathropteris obovata Oishi from the Late Triassic of Guangyuan, Sichuan Province, China. The specimens show round to oval and exindusiate sori, vertical to oblique annuli in sporangia, and in situ trilete spores with verrucate and baculate sculptures, which are comparable to dispersed spore genera of Converrucosisporites and Conbaculatisporites. Comparisons of relevant fossil taxa suggest that specimens of C. obovata from Triassic of China provide for the first time in Asia the detailed fertile structures with in situ spore characters of dipterid fossil Clathropteris. Unlike living Dipteris, Mesozoic fossils of Dipteridaceae show a high diversity and a range of complex morphology of in situ spores, thus are significant for the evolutionary links between Dipteridaceae and other related fern clade, including Gleicheniaceae and Matoniaceae of the Gleicheniales.

International audience; A study of the cheirolepidiaceous conifer Pseudofrenelopsis gansuensis from the Lower Cretaceous of Wangqing Jilin Province in China was conducted in detail using scanning and transmission electron microscopy techniques. In total, nine ultrastructural features were recognized for the cuticle of this fossil plant, which are helpful in the distinguishing between cuticles of ordinary epidermal cells, subsidiary cells, guard cells and hypodermal cells of the stomatal apparatus. A three dimensional reconstruction of the cuticle ultrastructure was obtained. Pseudofrenelopsis gansuensis is the second species of this genus for which the cuticle ultrastructure has been statistically examined with 30 measurements and estimated con␣dence interval values. The close comparison of the cuticle ultrastructure characters, including sta- tistical data, among Cheirolepidiaceae and other fossil conifers provides potential evidence of the taxonomic signi␣cance of this genus: ten characters are potentially valuable for speci␣c separation, eleven parameters for generic separation and three parameters seem also to be useful for Family determination. The differences in the chemical composition according to preliminary statistical element analyses of the cuticles based on three ratios in two species of Pseudofrenelopsis, P. dalatzensis and P. gansuensis, should also be examined in future studies.

Heterophyllous coniferous genera belonging to the family Cheirolepidiaceae are not always easily distinguished from one another morphologically. The taxonomically controversial genus Suturovagina from the Cretaceous of East China was studied by ultra-thin sectioning and examination under scanning and transmission electron microscopes. A detailed comparison between this genus and Pseudofrenelopsis was made based on cuticle micro- and ultrastructure as well as gross morphology. Suturovagina intermedia is among the few fossil coniferous plants for which cuticle and stomatal structures have been examined using both scanning and transmission electron microscopes and reconstructed using statistical data. Despite a slight overlap in gross morphology of leafy shoot , Suturovagina intermedia is well distinguished from Pseudofrenelopsis and all other cheirolepidiaceous conifers in cuticle and stomata micro- and ultrastructure, especially in the very deep stomatal chamber composed of tiers of subsidiary cells. The characteristic stomatal structure and the extremely thick cuticle with a wavy polylamellate layer in the cuticle proper also provide additional evidence for an xerothermic environment for the plant-bearing formation. The informative results of this study suggest that the potential taxonomic and palaeoecological significance of these features should not be neglected.

New specimens of Ginkgoites skottsbergii Lundblad collected from the Albian Kachaike Formation at the type locality in Santa Cruz Province, Argentina are characterized with additional scanning and transmission electron microscopic observations and EDS elemental analysis. The micromorphology of the amphistomatic and 12-segmented leaf of G. skottsbergii shows a smooth lamina with straight and pitted anticlinal and slightly granulate periclinal walls, abundant epicuticular wax on the petiole surface, and monocyclic to partially dicyclic stomatal apparatuses with between six and eight papillate to non-papillate, finely striated subsidiary cells and guard cells with smooth walls. Palaeoenvironmental considerations suggest that G. skottsbergii was a mesophytic plant. The TEM studies of ordinary epidermal cell cuticles and subsidiary and guard cell cuticles reveal the general ultrastructural features of Ginkgoaceae. Using confidence intervals based on 30 statistical measurements and the Mann–Whitney test for five measurements of EDS ratios of the elements, 33 ultrastructural characters were identified that enabled discussion at different taxonomic levels. Comparisons with the previously studied Ginkgoites ticoensis Archangelsky reveal that 14 of these characteristics could be species features that reinforce the identity of G. skottsbergii, and 19 could be genus features. EDS analysis and comparisons with G. ticoensis yielded five ratios using Cl, N, K, S, and Ca, revealing seven ratios of potential species interest and eight ratios at the genus level among the three zones evaluated in the leaf cuticle of each species. A three-dimensional reconstruction of the cuticle and an ultrastructural identification key for each of the three types of cuticle are also provided, i.e., from the ordinary epidermal cell and the subsidiary and guard cells of the stomatal apparatus. Fruitful statistical comparisons with two previously studied ginkgos allow discussion of the relationships within the Ginkgoaceae with respect to 18 features, six of them being potentially significant at the genus level and four at the family level. Fil: Guignard, Gaëtan. Université Claude Bernard Lyon 1; Francia. Centre National de la Recherche Scientifique; Francia Fil: del Fueyo, Georgina Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Villar, Liliana Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Carrizo, Martin Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Lafuente Diaz, Maiten Amalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

Isolated ovules from the Upper Triassic of Zimbabwe were observed using three complementary approaches: light microscopy and, for the first time, scanning electron microscopy and transmission electron microscopy. Complete ovules showed a curved bifid micropylar tube. Three envelopes were present: integument, nucellus, and megaspore. The integument appeared resiniferous. The nucellus was made up of bulging cells around the pollen chamber, which contained bisaccate pollen grains. The ultrastructure of the nucellus revealed a lamellar organization in their microsinuosities. The megaspore membrane was made up of agglomerate rounded bodies more or less closely arranged and surrounded by two layers. The material may be attributed to Umkomasiaceae. A comparison with ovules of different related groups (seed ferns, Caytoniales, Ginkgoales, Nilssoniales, and Coniferales) was made. The Umkomasiales are considered to be a more primitive group than the Pteridospermales with regard to integument and nucellus.

Studies of land plant spores/pollen include a large subject area of both living and fossil material. They impact on many areas of science, ranging from classical neobotany and palaeobotany, analysis of present and past environments and climate change, geological correlation of rocks, agronomy, medicine (allergy studies) and so forth. Advances in the scientific understanding of spores/pollen have to a large extent been driven by technical advances in microscopy (essentially the medium through which one observes these microscopic reproductive particles). One of the major technological advances that has impacted spore/pollen research was the development in the 1950s of commercially available transmission electron microscopy (TEM). This instrumentation enabled for the first time high powered magnification of sections of spores/pollen. This paved the way for the description of cellular features in extant spores/pollen, which made it possible to engage in studies of ontogeny (including exospore/exine development). The latter proved especially useful for taxonomic and phylogenetic analysis, especially as it can often be extended back into the rich spore/pollen fossil record. This paper provides a brief review of the historical development of spore/pollen research, and places in context the influence of Bernard Lugardon (1930–2007), one of the pioneers of TEM analysis of spores/pollen. Sadly Bernard passed away on the 26th January 2007. The papers collected in this special volume are dedicated to the memory of Bernard Lugardon.

The Gleicheniaceae is an ancient leptosporangiate fern family with fossil records dating back to the Palaeozoic. Fossil gleicheniaceous plants in China have received much attention and it has been suggested they play an important role for understanding the origin and evolution of the Gleicheniaceae. In this paper, the fossil diversity of gleicheniaceous plants is analyzed based upon systematic review of 27 species ascribed to six genera of fossils recorded from the Permo-Carboniferous to Cretaceous/Tertiary of China. The reproductive structures, including sori, sporangia, annuli and in situ spores (including their ultrastructure) are especially emphasized and discussed in a systematic and evolutionary context. The palaeogeographical distribution and stratigraphical ranges of these fossils are investigated based on detailed fossil records at the species level. Our study indicates that fossil gleicheniaceous plants in China have undergone evolutionary processes that include origin, decline, recovery and radiation, during different episodes from the Carboniferous to Cretaceous/Tertiary.

Dictyophyllum , a genus of the fern family Dipteridaceae, was widespread during the Triassic and Jurassic. However, the in situ spores are relatively poorly known. The specimens described here represent the first report of fertile fronds with in situ spores from Asia. Well-preserved and compressed specimens of the dipteridaceous fern Dictyophyllum nilssonii (Brongniart) Goeppert were investigated from the type locality of the Hsiangchi Flora in western Hubei province, southern China, collected from the upper part of the Lower Jurassic Hsiangchi Formation. Sporangia and in situ spores were examined using light and electron microscopes. The sporangia are rounded, 300–450 µm in diameter, with an oblique annulus. Each sporangium produces 220–280 trilete spores. These are triangular to subtriangular in outline, 40 µm in average diameter, with smooth exines, as well as interradial thickenings along the laesura situated on the proximal surface. The in situ spores are comparable to the dispersed trilete spore genus Dictyophyllidites . Preliminary observations on the ultrastructure of the in situ spores are reported, which supply clues for further investigation of the systematics and phylogeny of the Dipteridaceae. In addition, the ecological implications of Dictyophyllum and its associated ferns are briefly discussed.

Cuticular studies of Ginkgoites Seward from the Lower Cretaceous of Patagonia. The anatomy and ultrastructure of the leaf cuticles of Ginkgoites ticoensis Archang. and G. skottsbergii Lund. is studied. Both taxa were collected in Santa Cruz province, G. ticoensis from the Anfiteatro de Tico Formation (Aptian) and G. skottsbergii from the Kachaike Formation (Albian). The cuticular studies were made by means of electronic microscopy (SEM, TEM). These observations showed that G. ticoensis has hypostomatic leaves, papillae on both cuticles, and monocyclic stomata with 5-7 papillate subsidiary cells; while G. skottsbergii presents amphistomatic leaves, and monocyclic to dicyclic stomata with 6-8 subsidiary cells partially papillate. At the ultrastructural level the cuticular membrane has three layers, which are clearly distinct in both species. Comparisons with the leaf cuticle of other ginkgoalean taxa are also made.

International audience; This review of the genus Dichopteris De Zigno is based on the original fossil specimens collected from the Lower Jurassic of the Grey Limestones of Veneto (Northern Italy). The cuticular diagnosis of the genus is emended and only Dichopteris visianica De Zigno is retained within the genus. In addition, transverse and longitudinal sections of cuticles examined using a transmission electron microscope (TEM) indicate close similarities between D. visianica and other pteridosperm cuticles, especially the occurrence of granules arranged in areas of different densities in the epidermal cells and stomatal apparatus. Moreover, the dichotomy and the impressive size of the frond of D. visianica imply a specific architecture with a typical arrangement of the pinnae and pinnules. They preclude an herbaceous habit for the plant. Finally, architectural, microstructural and ultrastructural observations are consistent with palaeoclimatic and palaeoenvironmental data, and most probably support an understorey habit for D. visianica

Sphenobaiera huangii (Sze) Hsü is typical Early Mesozoic fossil foliage of Ginkgoales in China. It has been recorded from the Upper Triassic to the Lower Jurassic. The cuticular anatomy is investigated based on material from the type locality, Lower Jurassic Hsiangchi Formation, Zigui County, Hubei Province. The specimens are similar to S. huangii, but contain new information about leaf morphology and cuticular anatomy. Lower and upper cuticle is investigated using light and electron microscopy (LM, SEM, and TEM). Many features are described for the first time, including general structures of lower and upper cuticle, stomata, papillae, and cuticular ultrastructure. At the ultrastructural level, two layers have been distinguished in both lower and upper cuticle, including a homogeneous outer layer with granules and a heterogeneous inner layer with fibrils. Based on a literature comparison between S. huangii and other relevant species of Sphenobaiera, S. huangii may represent the best-known taxon in the genus Sphenobaiera in both leaf morphology and cuticular structures. This study provides the first detailed ultrastructural data on the leaf cuticle of Sphenobaiera, one of the oldest foliage taxa of Ginkgoales, and offers further evidence for potential discussion on the taxonomic relationships of S. huangii with other ginkgoalean taxa.

Cuticle micromorphology together with epidermal and epistomatal wax, in both current- and first-year-old needles of conifer Pinus halepensis (Aleppo pine) trees growing under volcanic gas fumigation was analysed in Pisciarelli area, Campi Flegrei, Southern Italy. As a control, current- and first-year-old needles growing far from volcanic gas emission were also sampled. Using a multidisciplinary approach with SEM, TEM and X-ray, volcanic gases were shown to cause degradation on epicuticular and epistomatal waxes. Significant statistical variations of ultrastructural components of the cuticle, with 30 measurements, including total thickness of the cuticle, and details and proportions of all different layers, and use of confidence interval, revealed a high degree of sensitivity of Aleppo pine to this extreme environment. In the present study, non-significant thickness variations of the cell wall plus cuticle among current- and first-year-old needles of both fumigated and non fumigated trees have been found. However, at the ultrastructural level, significant variations in cell wall and total cuticle thickness, especially within the three zones of B1 fibrillar layer, revealed different equilibria for each of the four types of material. Using energy dispersive X-ray microanalysis, no sulphur was found in either cuticle or epidermal cells, but the presence of H 2 S in the fumarole gas is suspected to cause indirect and/or direct cuticle alterations of wax structure. Ultrastructural characters of plant cuticles related to emission of volcanic gases during the geological past are also discussed. Among these considerations, an identification key enabling distinction between non fumigated and fumigated materials with 9 characters, provides a good tool detecting the influence of volcanism for extant and fossil plants.

Through a study of some selected sites, the group of pollen, Normapolles, extinct Angiosperms, appears to be an example illustrating the biodiversity in space, both in France and Czech Republic, as well as in time, from Cenomanian to Turonian. This first study shows an evolution, from a low biodiversity during the Middle Cenomanian, to an “explosion” of the number of forms in the late Turonian-early Coniacian. This biodiversity evolution seems to be linked to palaeoenvironmental changes, such as anoxic crisis, climate and/or eustacy...

Vegetative plant remains and microsporangiate cones, related to the fossil genera Frenelopsis and Classostrobus respectively, were studied in three localities from the Lower Cretaceous of the Pyrenees and Iberian Ranges (Spain). Sterile remains belong to three different species: F. Rubiesensis Barale, F. Ugnaensis sp. nov. and F. Turolensis sp. nov. The male cones Classostrobus ugnaensis sp. nov. and C. Turolensis sp. nov. are associated with the two latter species respectively, and C. Turolensis is found in connection with F. Turolensis. Internodes of F. Ugnaensis display small hemispherical papillae and long conical hairs covering the entire cuticle surface, while F. Turolensis has a strip of hairs near the leaf margin, in addition to more massive outer stomatal papillae and higher stomatal density. The tiny cones of C. Ugnaensis bear microsporophyll cuticles capped with vermiculate flattened papillae and a fringe of marginal hairs, while C. Turolensis has a central area of microsporophylls covered by long conical hairs. Sedimentological and taphonomic analyses show that the assemblages studied belong to a wide spectrum of habitats. These indicate that Spanish Lower Cretaceous frenelopsids were xeromorphic plants, able to adapt to helophytic and riparian habitats, and grew in brackish coastal marshes and fluvio–lacustrine freshwater environments.

Karkenia henanensis sp. nov. is found in association with ginkgoalean leaves of the Sphenobaiera type in the Jurassic Yima Formation, Henan, China. The material consists of five young strobili. The strobilus is compact, oblong to lanceolate, and contains more than 100 ovules. Ovules orthotropous, but incurved. The integument cuticle remains unknown, while it appears to be free from the nucellus in the greater part of the ovule. The megaspore membrane is composed of a thin, amorphous foot layer and a thick patterned layer. Bacula are irregularly arranged, finely granular in texture, but with electron-lucent lines in the matrix. Pollen grains found attached to the nucellus are of the Ginkgocycadophytus type. Comparisons have been made between the new species and the already described forms. The general morphology of the genus Karkenia is summarized with phenological consideration, taking into account the information obtained in the present study and in recent years as well. This is the first record of Karkenia in China. Possible records of this genus in China formerly described under Stenorachis are also enumerated. K. henanensis is one of the few fossil ginkgoaleans of which the megaspore membrane ultrastructure has been studied.

The in situ spore ultrastructure of fossil Marattia asiatica (Kawasaki) Harris, a common Early Mesozoic marattialean fern in Asia, is investigated using scanning and transmission electron microscopes based on the material from the Lower Jurassic Hsiangchi Formation in Hubei, China. The exospore consists of a thin inner layer, a thick homogeneous outer layer, and an intermediate zone (middle layer). The intermediate zone comprises some very thin sheets linked to the inner layer and interbedded with sporopollenin similar to that composing the outer layer and includes small cavities connected to the wall surface through narrow canals crossing over the outer layer. No perispore elements were observed in the investigated spores. Comparisons of the exospore ultrastructures, especially those of the intermediate zone in extant and fossil ferns, indicate close affinities between fossil M. asiatica and the extant Marattiaceae. Such affinities are less evident for the Paleozoic fossil record of marattialeans, probab...

Newly discovered coniferous shoots from the Cretaceous of Nanjing are attributed to the xeromorphic coniferous genus Glenrosa Watson and Fisher, which is found in China as well as in Eurasia for the first time. G. nanjingensis sp. nov. is known from shoots bearing scale-like leaves with thick epidermal cuticle and hypodermis. Stomata are confined to the abaxial surface deeply sunken in stomatal chambers which are filled with papillae. The cuticle, which has been sectioned for TEM, consists of an outer pale amorphous cuticle proper, usually with a peripheral polylamellate zone, and an inner dark cuticular layer containing reticulate fibrillae. G. nanjingensis sp. nov. bears a close resemblance to the type species G. texensis (Fontaine) Watson and Fisher from North America in gross morphology and especially in the characteristic stomatal chambers, but differs in phyllotaxis and in having the hypostomatic leaf with an obtuse apex. G. nanjingensis sp. nov. is believed to have grown near inland marshes or water bodies under hot and arid climates.

Resume Le comportement des phytocenoses continentales lors des couples crises-paleodiversifications est assezdifferent de celui des faunes marines, materiel habituel de l'etude de ces evenements. Souvent les periodes de diversifications ne sont pas concomitantes. Une approche globale du Phanerozoique et surtout, a une toute autre echelle, des etudes de flores terrestres du Jurassique et du Cretace inferieur permettent d'illustrer cette affirmation. L'evolution des plantes n'est pourtant pas independante de celle des facteurs ecologiques, tant biotiques qu'abiotiques. La diversification des angiospermes et des pinacees (gymnospermes) durant le Mesozoique est significative a ce titre. A cause de leurs particularites biologiques (sensu lato), les plantes ont des possibilites de speciation assez differentes de celles des animaux. Bien connues des geneticiens, ces possibilites sont trop souvent ignorees des, phylogeneticiens, quoiqu'elles temoignent de l'eventualite d'une evolution reticulee.

A study of well preserved fossil cuticle material of Hirmeriella muensteri from the Liassic of Franconia (Germany) was carried out using transmission electron microscopy (TEM), as well as scanning electron microscopy (SEM) and light microscopy (LM). The ultrastructure of normal epidermal cells is described as well as that of the stomata with a differentiation into guard and subsidiary cells. The ultrastructural details allow not only a discussion on the taxonomic position of the species, but also on the structure/function relationships, xeromorphism and the ability of the guard cells, and to a lesser degree of the subsidiary cells, to change in shape and volume for opening and closing.

The leaf cuticle of the Ginkgoites ticoensis Archang. type material from the Aptian Anfiteatro de Tico ́ Formation in Patagonia, Argentina, is fully characterized with additional scanning and transmission electron microscopic observations. Many new anatomical and ultrastructural cuticular features are identified in the four-lobed leaf of G. ticoensis: the leaf shows a hypostomatic and papillate laminae, straight and pitted anticlinal and granulate periclinal walls, actinocytic stomata with between five and seven papillate, striate subsidiary cells, and guard cells with anticlinal smooth walls. The TEM studies on ordinary epidermal cells, papillae, subsidiary cells, and guard cells reveal general ultrastructural features of Ginkgoaceae: an outer polylamellate layer A made with A1 and a granular inner layer A2; A1 with an upper part A1U with continuous and straight translucent lamellae; a lower part A1L with significantly disrupted and waving translucent lamellae; and the fibrillar cuticular layer B1 as the innermost part. Ten ultrastructural characters are detailed and ranked by the use of confidence intervals based on 30 statistical measurements. A three- dimensional reconstruction of the cuticle is also provided. Because of the anatomical and ultrastructural fine details shown in the G. ticoensis cuticle, new elements are given to suggest its probable family affinity and to enhance the specificities of Ginkgo and Ginkgoites. Fil: del Fueyo, Georgina Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentina Fil: Guignard, Gaëtan. Université Lyon 1; Francia. Centre National de la Recherche Scientifique; Francia Fil: Villar, Liliana Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentina Fil: Archangelsky, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentina

Epidermis micromorphology of in situ Erica arborea L. exposed for generations to long-term effect of volcanic gases in Pisciarelli and Solfatara di Pozzuoli areas have been studied by X-ray analyses, SEM and TEM observations. In particular, the aim of this study is to investigate the effects of volcanic gases on extant and possibly fossil plants. Plants of the same species living in a nearby control site were also studied for comparison. SEM coupled with EDX analysis was used to localize different elements within the leaves (mesophyll, cell wall and cuticle). After conventional and cryo preparation, SEM of mature leaves ascertained that the abaxial side is more serrate in fumigated leaves and hairs, epicuticular wax alterations have also been noted. Leaves experiencing chronic fumigation display stomata more sunken with respect to the epidermal surface. TEM of transverse and longitudinal sections of cuticle showed an outer A2 granular amorphous layer and external to a B1 fibrillous layer. Significant statistical variations of ultrastructural components of the cuticle revealed a response of E. arborea to this extreme environment. At the ultrastructural level, significant variations in thickness of the cell wall plus cuticle, cell wall and A2 layer among fumigated and non-fumigated leaves have been found. In the studied localities a positive correlation between atmospheric CO2 concentration and the thickness of A2 layer also exists. The results are of interest being applicable in the understanding of plant cuticle responses during periods of normal vs. volcanic activity. © 2012 Elsevier B.V.

Chiron, G. R., G. Guignard & G. Barale (2010). Contribution of morphometry to the taxonomy of Baptistonia Barb. Rodr. (Orchidaceae). Candollea 65: 45–62. In English, English and French abstracts. The genus Baptistonia Barb. Rodr. (Orchidaceae) includes 23 species, all endemic to Brazil. As problems occur to differentiate some taxa of this genus, because of their hypothetical hybrid origine, the present study aims to use morpho metry as an attempt to solve these issues. Twenty six floral morphometric characters were measured on 146 specimens, and analysed using multivariate analysis, such as Neighbour Joining Analysis (NJA), Principal Coordinates Analysis (PCoA) and Discriminant Analysis (DA). Morphometric data proved to be very useful for species delimitation, and a statistical tool here is presented in clearly separating taxa within the confusing groups. Hybrid nature of two species is presented. The contribution of morphometry in phylogeny for Baptistonia is discussed.

Based on sections from both macerated and unmacerated cuticles and, for the extant species, the leaf cuticles from male and female trees, we investigated the leaf cuticle ultrastructure of Ginkgo biloba and Ginkgo yimaensis from the Jurassic of Yima, China. All of the cuticles were cut in two different directions: perpendicular and parallel to the leaf length. The cuticular membranes of both fossil and living species were generally similar, each having a cuticle proper and a fibrillar cuticular layer. The cuticle proper may be divided into an outer peripheral polylamellate layer and an inner, mainly granular, layer. In the upper part of the polylamellate layer, the lamellae were more regularly arranged than in the lower part. Comparisons of macerated and unmacerated cuticles show that the cuticular layer became thinner after treatment with chemical agents. Examining sections in different directions is important for studying leaf cuticular ultrastructure because of the considerable variation. Available evi...

Exceptional preservation of extinct Pachypteris extra-epidermal cuticle enabled the first detailed statistical measurements of its ultrastructure using transmission electron microscopy. Pachypteris is a leaf genus of the Mesozoic belonging to seed fern foliage of the order Corystospermales. The species studied in this paper is Pachypteris gradinarui Popa [Rev. Palaeobot. Palynol. 111 (2000) 31], based on fossils which are Early Jurassic in age (Hettangian-Sinemurian, approximately 205-190 million years old). Both the upper and the lower cuticles were thoroughly examined, including the detail of the stomatal complexes and epidermal cells. The data obtained from our TEM analysis, together with the confidence intervals, were very useful to give precise description of the cuticles as they distinguished between upper and lower epidermal and stomatal cell types. Moreover a combination of characters was used to develop the first dichotomous key based on ultrastructural characters, i.e. not only the total thickness of the cuticle but also details and proportions of A cuticle proper and B cuticular layer. Comparisons with ultrastructures known from other Pachypteris species show that the influence of space and time, diagenetic processes, and/or processes related to technical procedures, seem to be minimal within this genus. Detailed studies of this type may be very useful for further comparisons among other species and at higher taxonomical ranks.

An ultrastructural transmission electron microscope (TEM) study of fossil leaf cuticles from the Jurassic pteridosperm Komlopteris nordenskioeldii (Nathorst) Barbacka from the Mecsek Mountains (South Hungary) was conducted. Remnants of cuticles of leaves originating from so-called “sun and shade” environments were sectioned with a diamond knife, transversally as well as longitudinally. Although the present study showed a simple type of cuticle in this pteridosperm, differences were observed in the occurrence of its components, such as electron lucent amorphous material and various densities of granules, which give rise to different zones. The included fibrilous elements appeared to be made of aggregated and aligned granules, equivalent in size and electron density to nearby non-fibrilous granular regions. The combinations of these ultrastructural features allow distinctions between four types of cuticle: sun upper, sun lower, shade upper and shade lower. Considering the distinction made earlier in two types of cuticle and supposed to be related to sun and shade on the basis of macroscopical and microscopical features, four types only on the basis of differences in thickness, the present study reinforces the distinctions with ultrastructural microcharacteristics. As this study shows the variations in ultrastructure of cuticle among the four types, the differences observed may reveal the great sensitivity of some plants to environment. At the same time, it points out the importance, in ultrastructural studies of cuticles, of studying a number of samples for one taxon.

Though the fossil genus Oligocarpia is generally regarded to be of gleicheniaceous affinity, nothing is currently known about its spore ultrastructure. In this article, the micromorphology and ultrastructure of in situ spores of gleicheniaceous affinity are investigated for the first time with scanning electron microscopy and transmission electron microscopy from a compression specimen of Oligocarpia kepingensis Wang and Wu collected from the Lower Permian of Xinjiang, northwest China. Spores of O. kepingensis closely resemble the dispersed taxon Leiotriletes (Naumova) Potonié et Kremp. At the ultrastructural level, the exospore consists of three-layered subdivisions, including a degraded and weakly preserved thin inner layer, a complex and elaborate middle layer, and homogeneous outer layer. Comparisons are made between Oligocarpia spores and those of other related fossils, as well as extant taxa based on morphological and ultrastructural evidence. These data indicate that, despite clear differences in leaf morphology, O. kepingensis has a close relationship to the family Gleicheniaceae.

Rare plants from Dombes (Ain, France) During 1995, a prospection of Dombes ponds tried to define the status of their rare vascular plants. Some precocious species are commonly overlooked by botanical investigations, in Dombes tradionnally taking place during late August and September. Other species are unrecognized whereas the status of some others have recently changed. At last, results are given for some rare species not typical of ponds., En 1995, une prospection des étangs dombistes a tenté de cerner le statut des plantes vasculaires rares des étangs de la Dombes. Certaines espèces précoces sont communément occultées par les prospections habituellement tardives des botanistes en Dombes (août et septembre). D'autres sont méconnues. D'autres encore ont un statut qui a beaucoup changé récemment. Quelques résultats sont enfin présentés pour des espèces rares non inféodées aux étangs., Curtet Laurence, Guignard Gaëtan, Philippe Marc. Plantes rares de la Dombes (Ain, France). In: Bulletin mensuel de la Société linnéenne de Lyon, 66ᵉ année, n°4, avril 1997. pp. 93-104.

Seeds of most species in the genus Digitalis were studied by scanning electron microscopy, with particular reference to the micromorphology of the cells of the outer layer of the seed coat as well as seed size and weight. Four types of seeds, corresponding to four of the five recognized sections of the genus (Digitalis, Macranthae, Tubiflorae, and Frutescens), were distinguishable. The fifth section, Globiflorae, shows some affinities with Tubiflorae and Frutescens. The taxonomical importance of these seeds is discussed as are similarities between groupings of seeds and phylogeny in this genus.

ResumeA partir d'une etude morphologique de populations de dactyle, l'auteur decrit un taxon nouveau sur le littoral atlantique.

Silica bodies were observed in populations belonging to four tetraploid taxa of the genus Dactylis. Twelve characters were used to describe those elements, which allow some comparisons to be made between populations growing wild and those growing in experimental plots. They also show the taxonomic importance of the silica bodies. This new approach leads to both a confirmation and a better understanding of the morphological affinities previously observed among the different taxa.

A statistical study of four criteria applied to the genus Dactylis (Poaceae) enabled us to determine the individual meiotic behaviour of eight tetraploid populations. Those criteria were as follows: the percentage of rod and ring bivalents, the average number of tetravalents, the average number of chiasmata, and the distribution pattern of chromosomic formulas.Key words: Dactylis, populations, meiotic behavior, tetraploidy, cocksfoot.

Guignard Gaëtan. Structure et division du noyau cellulaire. In: Bulletin mensuel - Société botanique de Lyon, tome 2, bulletin 4, 1884. pp. 52-60.

Guignard Gaëtan. Compte rendu des travaux de la Société en 1885. In: Bulletin mensuel - Société botanique de Lyon, tome 3, bulletin 4, 1885. pp. 137-141.

Guignard Gaëtan. Stérilité comparée des organes reproducteurs des hybrides végétaux. In: Bulletin mensuel - Société botanique de Lyon, tome 4, bulletin 3, 1886. pp. 66-75.

Guignard Gaëtan. Sur le sac embryonnaire. In: Bulletin mensuel - Société botanique de Lyon, tome 2, bulletin 3, 1884. pp. 31-35.