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Background and aims: In Argentina, the genus Bambusa comprises nine introduced taxa, of which the most cultivated are B. multiplex, B. tuldoides and B. vulgaris cv. vittata. Bambusa plants are characterized by non-seasonal blooms, after long and variable vegetative periods. The study of the foliage leaf anatomy of woody bamboos is thus usefulness in the taxonomy of Bambusoideae. In order to characterize each species, the micromorphology, anatomy, and ultrastructure of foliage leaf blades are studied. M&M: With the aid of optical, scanning electron and transmission electron microscopy, the anatomy of foliage leaf blades of the three species are analysed. Qualitative and quantitative parameters of transverse and longitudinal sections and dissociated material are documented. Results: The dimensions of the leaf blade showed significant differences between the three species of Bambusa studied. The micromorphology of the foliage leaf blade surface exhibits differential characters between the abaxial and adaxial epidermis between species, such as the presence or absence of microhairs, macrohairs and prickles; silica cell type; degree of cohesion and number of papillae surrounding the stomatal apparatus. The dimensions and characteristics of the fusoid cells and fibers show differences between the species, as well as the micrometric parameters as seen in cross sections. Conclusions: The morphoanatomical features allows the characterization of the Bambusa species studied. [ABSTRACT FROM AUTHOR]

Summary: The pinnately lobed Aptian leaf fossil Mesodescolea plicata was originally described as a cycad, but new evidence from cuticle structure suggests that it is an angiosperm. Here we document the morphology and cuticle anatomy of Mesodescolea and explore its significance for early angiosperm evolution.We observed macrofossils and cuticles of Mesodescolea with light, scanning electron and transmission electron microscopy, and used phylogenetic methods to test its relationships among extant angiosperms.Mesodescolea has chloranthoid teeth and tertiary veins forming elongate areoles. Its cuticular morphology and ultrastructure reject cycadalean affinities, whereas its guard cell shape and stomatal ledges are angiospermous. It shares variable stomatal complexes and epidermal oil cells with angiosperm leaves from the lower Potomac Group. Phylogenetic analyses and hypothesis testing support its placement within the basal ANITA grade, most likely in Austrobaileyales, but it diverges markedly in leaf form and venation.Although many Early Cretaceous angiosperms fall within the morphological range of extant taxa, Mesodescolea reveals unexpected early morphological and ecophysiological trends. Its similarity to other Early Cretaceous lobate leaves, many identified previously as eudicots but in some cases pre‐dating the appearance of tricolpate pollen, may indicate that Mesodescolea is part of a larger extinct lineage of angiosperms. [ABSTRACT FROM AUTHOR]

In spite of the worldwide ecological relevance of Calanus australis and Calanoides carinatus , little is known on the morphology of their mandibular gnathobase edges (MGEs). Thus, in order to further learn about the relationship between MGEs and diet, adults and copepodites of C. australis and C. carinatus collected from northern Patagonian coasts, Argentina, were morphologically analyzed using confocal laser scanning microscopy in transmission mode and scanning electron microscopy. In C. australis males as well as in C. australis and C. carinatus females, MGEs were found to end in one dorsal seta and to have one ventral tooth, four central teeth and three dorsal teeth. In contrast, in C. carinatus males, MGEs were observed to be rudimentary and with no dorsal seta, and −contrary to published data− they were found to have three cone-shaped, short and small tooth-like structures and three-four tooth-like structures that were long and pointed. The main differences between MGEs from copepodites and adults of C. australis and C. carinatus females lied in the number of cuspids observed on the different teeth and the presence of a short inner lateral peak found only in C. australis ventral tooth. Overall, the evidence gathered from our study leads us to classify C. australis and C. carinatus as omnivores. [ABSTRACT FROM AUTHOR]

New cuticle samples from the bennettitalean Ptilophyllum eminelidarum were herein studied using the combination of light microscopy (LM), scanning and transmission electron microscopy (SEM, TEM), and element analysis by Energy Dispersive Spectroscopy (EDS). The new TEM studies correspond with and improve the former ones; however, statistical measurements reinforce their uniqueness and erect Bennettitales as a heterogeneous group of cuticles. Six types of cuticles were recognized. According to the factorial component analysis (FCA), the cuticles of the stomatal apparatus show the highest level of interest, while the epidermal cell cuticles, the lowest. For the 9 variables, the top 6 as to importance were the most independent, which could be used as criteria for identification in Bennettitales. A dichotomous key was built, allowing for a rapid identification of each of the 6 types of cuticles based on the 9 variables. Showcasing an upper cuticle significantly thicker and more exposed, and a thinner lower cuticle that is normally more protected, the micropalaeoenvironment of these leaves is of interest. The taxonomical identity of the present taxon is also revealed by the EDS values; S/Ca ratio is homogeneous for all layers of both cuticles, leading to assume, with extreme precaution, a putative similar influence of the palaeoenvironment on these two opposite surfaces of the leaf. As the first detailed statistical TEM and EDS for the Bennettitales, it highlights the great interest of this type of studies and the strong interest for revealing the characters of each type of cuticle and layer. [Display omitted] • New data for Ptilophyllum eminelidarum Bennettitales, Lower Cretaceous of Patagonia. • 6 types of cuticles defined with TEM, with detailed 9 variables of layers. • Cuticles' and layers' hierarchy, with multidimensional analyses and Student's t-tests. • Dichotomous key allowing a rapid identification of each type of cuticle. • Sulfur/Calcium ratio through EDS, homogeneous for all layers. [ABSTRACT FROM AUTHOR]