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Volcanic activity in ancient Mesoamerica was decisive for many populations since it influenced daily life and the way of understanding the world. Eruptive events can provoke the total or partial abandonment of the sites, changes in the social organization, and, inclusively, changes in the pedogenesis with alteration of the natural resources. The impact of volcanic activity can be detected easily. However, it can also be “hidden” among the soil and archaeological materials; consequently, its identification and analysis are essential to understanding archaeological stratigraphy. To document the above, this work presents the results obtained at two sites in western Mexico: Cerro del Teúl in Zacatecas (ca. 100-1531 d.C.) and El Pitayo in Michoacán (200- 600 d.C.). In the case of Cerro de Teúl, the construction fills were analyzed in two stratigraphic profiles: the Patio Hundido (PH21) and the Main Plaza (P2M80). In El Pitayo, construction fills and soil horizons were analyzed in two profiles located in a trench with an E-W orientation (East Trench and South Trench). The main objective was to identify the impact of volcanic activity on the archaeological stratigraphy and the transformations of volcanic materials as a consequence of natural and anthropogenic processes, using colorimetric, granulometric, and micromorphological analyses. In addition, the chemical composition (by X-ray fluorescence) and the petrography of the volcanic ash found in the sites were determined and compared with that from surrounding volcanoes. According to the results, the ash observed in Cerro Teúl originated from the Jala eruption of the Ceboruco volcano, dated 990-1020 AD. This eruption did not produce the site abandonment, as the site was rapidly re-occupied, and the ash was left between the construction fills. In the case of El Pitayo, according to archaeological evidence (the ages of the abandoned artifacts and the absence of volcanic glass on the lower floors of the construction), it is probable that the landslide was emitted during the first half of the 6th century and the site contin- ued developing after the event. The geochemical and mineralogical composition of the volcanic materials found in the excavations has an intermediate-acid affinity, which contrasts with the monogenetic volcanism in the area; however, as the material is reworked, it is probable that the original mineralogical composition has been modified by transport and erosional processes, or diluted by the mixture with more acid sources, as evidenced by the domain of volcanic glass with heterogeneous textures and morphologies. Until now, there is a possible source of emission of the volcanic material associated with that found in the “black earth” at the site of El Pitayo, which is the El infiernillo volcanic event, located south of Michoacán and which has a date of 1500- 1370 BC (Mahgoub et al., 2017). However, the “black earth” that covered the site is after this dating, so chronologically it would not correspond to an eruption that occurred during the occupation of the site, but it allows us to associate it as a product of a landslide from Cerro El Arco, since that the geochemical characterization of the volcanic glass shows a very close affinity to this El Infiernillo event.

Aerenchyma is a characteristic tissue of aquatic plants, characterized by the presence of air lacunae commonly septated by diaphragms. These are formed by one or more layers of stellate cells, which allow for the passage of gases. Most species of Eleocharis grow in wet or flooded soils and have aerenchyma in their aerial stems. However, extensive studies on this structure, which could contribute to ecological and phylogenetic studies of the group, are lacking. This work describes the structure of the diaphragm in the stem of Eleocharis species and investigates the evolution of this characteristic in the genus. Fifty-three species were analyzed under light and scanning electron microscopy. We analyzed the evolution of the characteristics by reconstructing their ancestral states based on the previously published original phylogeny. The diaphragms in Eleocharis vary mainly in the number of layers, cell shape, and cell wall thickness. The typical diaphragm of the genus is composed of three to four layers of stellate cells, with microprojections and secretory cells. The diaphragm of the group's ancestor had practically the same characteristics as the genus's typical diaphragm. [ABSTRACT FROM AUTHOR]

Morphoanatomy and histochemistry of Baccharis palustris: insights into a highly endangered endemic species from Southeastern America. The phenotypic plasticity of the Baccharis genus makes species identification difficult, even at the flowering stage. In this context, morphoanatomical studies are a powerful tool for botanical authentication, mainly emphasizing the recognition of diagnostic characteristics that may be useful for distinguishing similar species. Given the limited knowledge available about the endemic species B. palustris, this work aimed to characterize the morphoanatomy and histochemistry of its vegetative aerial parts to identify characters with diagnostic value and to elucidate the sites of synthesis and accumulation of metabolites of medicinal importance. B. palustris leaf showed pinnate, camptodrome-brochidodrome venation patterns. Blade with dorsiventral mesophyll, aerenchymatous spongy parenchyma, collateral vascular bundles, and different types of stomata and trichomes, including glandular trichomes with a multi-layered base evidenced and described for the first time in the genus. The petiole was winged, with three collateral vascular bundles. The stem showed a penta-lobulated contour with unusual growth, starch, and crystals in the pith. The presence of secretory ducts and glandular trichomes, which synthesized lipids, terpenes/polyacetylenes, and phenolic compounds, was observed. The morphological/histochemical characteristics described in this work contribute to the knowledge of the species, highlighting the importance of its preservation as a valuable resource. [ABSTRACT FROM AUTHOR]

Renealmia comprises approximately 85 herbaceous and rhizomatous plants in Africa and America known for their metabolite diversity. This study characterized the anatomy and histochemistry of the vegetative organs of three native Brazilian Renealmia species, R. breviscapa and R. nicolaioides, collected from the Amazon Forest in Acre and R. chrysotricha from the Atlantic Forest in Rio de Janeiro. Samples were fixed and processed using conventional plant anatomy and micromorphology techniques, including histochemical tests to identify classes of compounds in vegetative organs. Characteristics including oil idioblasts, dorsiventral leaf structure, tetracytic stomata, unicellular trichomes, and prismatic crystals were common among the studied species of Renealmia, and thus significant for the family. Distinctive characteristics were identified in the vegetative organs of the three species, including the cellular distribution of root phloem, covering of rhizome tissue, different types and distributions of idioblasts and phenolic trichomes in rhizomes and leaves, presence or absence of petiole, and subepidermal layer in the intercostal region of leaves. Mineral content importance as a diagnostic characteristic of the genus is also emphasized. The results of this study advance the understanding of the distinctive anatomical characteristics of the three species of Renealmia in different environments, two in the Atlantic Forest and one in the Amazon Forest. [ABSTRACT FROM AUTHOR]

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Epicuticular waxes crystallize on the foliar surface with different morphologies, which can be taxonomically relevant features in many taxa. Their morphological analysis was based on scanning electron microscopy (SEM) images on herbarium specimens of selected sections of Mimosa. The present work is the first detailed description and classification of the epidermal micromorphology in the genus Mimosa, focusing on section Calothamnos and Mimosa series Mimosa, subseries Dolentes and Brevipedes. We also describe different wax crystallization morphologies present in these taxa, identifying three different crystallization types: film, plates, and platelets. Novel epidermal micromorphologies have been described, such as papillae in M. lepidorepens. Results allow grouping taxa of the studied sections, contributing to clarifying their taxonomy. SEM images of epicuticular waxes and leaf surfaces could be a new tool for performing a new taxonomic treatment of section Mimosa subser. Dolentes and subser. Brevipedes, and section Calothamnos. [ABSTRACT FROM AUTHOR]

This research compares results of micromorphological case studies conducted on four early medieval archaeological sites with differentiated spatialization of human impacts and a varied craft production located in different background environments: humid climate, subzone of mixed forests, floodplain of the Dnieper River (Gnezdovo site); semi-humid climate, subzone of forest-steppe, Middle Volga region (Muromsky Gorodok and Malaya Ryazan' sites); arid climate, cold desert of the Aral region, ancient delta-alluvial plain of the Syr-Darya River (Dzhankent site). Micromorphological studies of habitation deposits revealed clear geographical and geochemical regularities in the occurrence of geogenic (soil, sedimentary and post-sedimentary) features. Intrasoil migration and accumulation of clay and coarser silicate material in textural pedofeatures were described in cultural layers of sites located in forest and the forest-steppe zones. An anthropogenic input of phosphates provokes simultaneous migration and illuvial accumulation of phosphates and clay. In the habitation deposits in steppe landscapes with calcareous lithology, the key background soil process is redistribution and intrasoil accumulation of calcium carbonates. In the alluvial desert landscape, major soil processes are accumulation of gypsum and readily soluble salts. All layers are or were affected by at least some seasonal over-moisturizing that resulted in a variety of redoximorphic features depending on their palaeo- and/or contemporary water regime. The high variety of anthropogenic processes and corresponding microfeatures was grouped as follows: (1) input, output, turbation, compaction; (2) neoformation and migration; (3) pyrogenic processes (products); technological processes (products). The set of anthropogenic features records past human impact in the locality. The higher the variety of anthropogenic features and their general abundance is, the more intensive and variable the human impact which had occurred in the past. At the same time, the occurrence of certain anthropogenic features may indicate not only human-related processes of their formation (or input), but also a contemporary soil environment. This environment can be favorable, or, in the opposite, deteriorative for earlier formed anthropogenic features. [ABSTRACT FROM AUTHOR]

This paper presents a micromorphological analysis of a sample series from three Mesoamerican earthen architecture sites. It compares a soil, a sample from a construction fill and a sample of a soil mixture used for mud-brick and facing, resulting from different manufacturing steps. The purpose is to identify the soil features that remain and those that are transformed in the process. This is of interest both to geologists, who encounter anthropically modified soils, and archaeologists interested in understanding the provenance of the raw materials and the manufacturing processes. In contrast to previous research based predominantly on earthen architecture from Europe and the Near East, this study is the first comparative analysis of Mesoamerican sites, where earthen construction developed independently from the Old World, using volcanic soils developed in a range of tropical environments. The results show that similar building techniques existed in different environments, that the non-expansive clays and fine fraction derived from volcanic deposits may have presented advantages for construction, while some features reflect the addition of mineral or vegetal temper to improve the mechanical properties of some soils. [ABSTRACT FROM AUTHOR]

As espécies de Wunderlichia (Asteraceae) são endêmicas das regiões central e leste do Brasil, geralmente encontradas em afloramentos rochosos e sujeitas a altas irradiação solar e temperatura. Tais condições sugerem ocorrência de múltiplas adaptações xeromórficas em Wunderlichia azulensis. Este estudo visou caracterizar a morfoanatomia dos órgãos vegetativos de W. azulensis. Raízes, caules e folhas foram coletados de um afloramento rochoso no Maciço do Itaoca, Campos dos Goytacazes, RJ, Brasil. O material vegetal foi fixado, desidratado e emblocado em resina plástica para seções transversais. Testes histoquímicos foram realizados para identificação das classes químicas nas folhas e tricomas de W. azulensis. A morfologia dos tricomas foi avaliada em microscópio eletrônico de varredura. As raízes apresentaram uma estrutura morfoanatômica distinta que pode ser caracterizada como xilopódio. As folhas apresentaram um conjunto de atributos anatômicos adaptativos, como células epidérmicas com paredes anticlinais retas ou levemente sinuosas, alta densidade de tricomas e camada subepidérmica. Os testes histoquímicos revelaram substâncias fenólicas e óleos essenciais no mesofilo. Este estudo contribuiu para o conhecimento sobre as adaptações anatômicas das plantas rupícolas e de ambientes xeromórficos, e sugere futuros estudos para elucidação da estrutura das raízes e caules de W. azulensis.

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]

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Introducción y objetivos: En Argentina, el género Bambusa está representado por nueve taxones introducidos, de los cuales los más cultivados son B. multiplex, B. tuldoides y B. vulgaris cv. vittata. Los representantes del género se caracterizan por tener floraciones no estacionales, luego de largos y variables períodos vegetativos. El estudio de la anatomía foliar de bambúes leñosos resulta de utilidad para la diferenciación de especies. Con el fin de caracterizar cada entidad, se estudia la micromorfología, anatomía y ultraestructura de sus hojas de follaje. M&M: Mediante microscopía óptica, electrónica de barrido y de transmisión se analizan los caracteres de los tipos celulares y de la estructura interna de las hojas de follaje de las tres especies. Se registran parámetros cualitativos y cuantitativos de cortes transversales y longitudinales y disociados de cada una de las especies. Resultados: Las dimensiones de la lámina de la hoja mostraron diferencias significativas entre las tres especies de Bambusa estudiadas. La micromorfología de la superficie foliar exhibe caracteres diferenciales entre la epidermis abaxial y adaxial de cada especie y entre especies: presencia o ausencia de micropelos, macropelos y aguijones; tipo de células silíceas; grado de cohesión y número de papilas que rodean a los estomas. Las dimensiones y características de las células fusoides y fibras muestran diferencias entre las especies, al igual que los parámetros micrométricos registrados sobre los cortes transversales de las hojas. Conclusión: Los caracteres morfo-anatómicos en conjunto con aquellos morfológicos permiten la caracterización de las especies de Bambusa estudiadas.

El estado de Tlaxcala, México, presenta problemas ambientales relacionados con la erosión del suelo; sin embargo, en algunas áreas conformadas por Andosols, bosque de pino y zonas agrícolas, su degradación es mínima. La presencia de micelio abundante en los horizontes subsuperficiales en suelos localizados en pendiente puede ser causa que los suelos se conserven. Los objetivos del estudio fueron caracterizar las propiedades edáficas de suelos en diferente posición geomorfológica, identificar especies de hongos micorrízico arbusculares (HMA) y determinar la relación del micelio con los agregados y las partículas elementales en un Vitric Andosols de Calpulalpan, Tlaxcala, México. Los resultados muestran que los suelos presentaron diferentes secuencias y espesores de cenizas y lapillis pomáceos, de moderada a alta fertilidad. La estructura migajosa dominó en horizontes superiores y granular simple en sub-horizontes. Los horizontes presentaron retención alta de humedad y permeabilidad facilitando el desarrollo micelial y formación de esporas de HMA hasta 120 cm de profundidad. Se registraron 10 especies de HMA y la mas abundante fue Funneliformis mosseae. El análisis micro-morfológico mostró diferentes relaciones entre el micelio, los horizontes y las partículas del suelo, con residuos orgánicos (horizonte O), macro y micro agregados (horizontes A y B), alófano e imogolita (horizonte B) y lapillis (horizonte C). El micelio de los hongos formó redes en todo el suelo y en los lapillis inserta a las partículas de pómez (como cuentas de rosario) a través de los poros vesiculares tubulares lo que le proporciona estabilidad a los Andosols y evita su degradación.

Esse trabalho teve como objetivo apresentar um modelo evolutivo para encosta em unidade de relevo de baixa ordem na Superfície de cimeira de Pinhão/Guarapuava, com base na reconstrução morfoestratigráfica e pedossedimentar das formações superficiais. Para tanto, foi descrito seção estratigráfica que, em conjunto com análises laboratoriais, permitiramestabelecer os processos morfogenéticos e evolutivos ao longo do Quaternário Superior. Os resultados indicam sequência estratigráfica constituída por paleossolo enterrado na base, sobreposto por três sequências coluviais e uma sequência colúvio-aluvial. As descrições pedoestratigráficas dos níveis sedimentares indicaram a presença de nove horizontes pedoestratigráficos, cuja gênese e evolução é função da dinâmica entre pedogênese e morfogênese ocorrida no final do Pleistoceno e ao longo do Holoceno. Os dados obtidos pela descrição micromorfológica sugerema atuação de escoamento superficial e fluxos gravitacionais no retrabalhamento dos materiais ao longo da encosta. Tais fenômenos foram correlacionados aos resultados encontrados para a Superfície de Palmas/Caçador, setor guia de sinais paleoambientais regionais das superfícies de cimeira do Planalto Vulcânico na região sul. As idades obtidas por meio de 14C e LOE sugerem que a morfogênese atuou desde o final do Último Máximo Glacial até o Holoceno, materializados sob depósitos de colúvio e colúvio-alúvio. No Holoceno Médio registra-se incisão erosiva linear (voçorocas), cuja colmatação ocorreu ao longo do Holoceno Superior (MIS 1). A pedogênese progressiva atuou principalmente no Último Máximo Glacial, e entre os episódios de sedimentação das unidades coluviais. Em conjunto, a atuação da morfogênese e pedogênese regressiva provocaram parcial inversão do relevo, decorrente da erosão dos materiais da alta/média encosta e sedimentação na média/baixa encosta.

Neste trabalho utilizou-se da caracterização micromorfológica para a compreensão dos processos de colmatação de paleocabeceira de drenagem ((paleofundo de vale de zero ordem) na Superfície de Pinhão/Guarapuava. Com base na caracterização macroscópica, foram reconhecidas quatro sequências sedimentares que preenchem a paleocabeceira de drenagem: paleossolo enterrado com topo acumulativo, sequência inferior colúvio-aluvial (co-alúvial), sequência colúvial intermediaria e sequência colúvial superior. Foram coletadas amostras indeformadas para análise micromorfológica, a qual contou com nomenclatura e critérios descritivos de Stoops. Como resultados, verificou-se a distribuição relativa dos constituintes (DRC) do tipo integrada (enáuli-porfífica e porfiro-enáulica), sinalizando diferentes fluxos no processo de sedimentação. A DRC enáulica apresenta agregados granulares e, em microagregados, indica escoamento superficial. Já a DRC porfírica exibe microestrutura maciça, sinalizando fluxos densos, possivelmente fluxos de lama. Os materiais que compõem a sequência colúvio-aluvial (co-alúvio), sequência colúvial intermediaria e topo do paleossolo enterrado são provenientes de escoamento superficial. A partir da sequência colúvial superior predominou o processo de fluxos de lama que levou à colmatação da paleocabeceira com a sequência colúvial superior.

Introducción: La Reserva Ecológica del Pedregal de San Ángel (REPSA) corresponde a un matorral xerófilo. En ella, los helechos y licofitas crecen en diversos microhábitats. En esta zona se han realizado investigaciones ecológicas y taxonómicas de la vegetación donde se han incluido las pteridofitas, sin embargo, no existen estudios palinológicos para este grupo de plantas. Pregunta: ¿Cuál es la micromorfología de las esporas de las especies de helechos y licofitas de la REPSA? Especies bajo estudio: Helechos y licofitas. Sitio de estudio: Zona Núcleo Poniente (ZNP) de la Reserva Ecológica del Pedregal de San Ángel, Ciudad Universitaria, Ciudad de México, México. Agosto 2013 a septiembre 2016. Métodos: Se recolectaron en campo ejemplares de referencia de helechos y licofitas, se identificaron y se depositaron en el Herbario Nacional (MEXU). Se obtuvieron las esporas a partir de pinnas fértiles, se montaron para observarse y medirse en microscopía fotónica (MF) y microscopía electrónica de barrido (MEB). Se obtuvieron las microfotografías y se realizó la descripción palinológica. Resultados: Se presenta la palinología de 23 especies de helechos y dos de licofitas, correspondientes a 16 géneros. Se describe por primera vez la micromorfología de las esporas de: Gaga decomposita, G. membranacea, Myriopteris allosuroides, Pellaea cordifolia, Pellaea villosa, Pleopeltis thyssanolepis, Ophioglossum engelmannii y Selaginella sartorii. Para las restantes especies se complementa y/o corrobora la micromorfología. Conclusiones: Los datos aportados contribuyen al conocimiento palinológico de las especies de licofitas y helechos presentes en la REPSA, y son caracteres de gran utilidad para la taxonomía de las especies.

La cuenca de los Bajos Submeridionales consiste en un extenso sistema hidrológico para el cual han sido propuestas distintas áreas de aporte sedimentario, así como también, procesos geomorfológicos controlados por la dinámica climática y tectónica regional. Con la finalidad de profundizar en el conocimiento de la génesis y distribución de los materiales parentales y suelos en el sector noroccidental de la cuenca, se estudia la micromorfología, la composición mineralógica y se discuten datos analíticos físicos y químicos de cuatro perfiles de suelo desarrollados en diferentes posiciones del paisaje. Los resultados muestran que en general los horizontes superficiales son los de textura más fina, no obstante los elevados valores de la CIC de la fracción arcilla y la humedad equivalente, sugieren una subestimación del porcentaje de las fracciones finas en el análisis granulométrico de los horizontes subsuperficiales. En tanto los estudios microscópicos constataron la presencia de pseudo-arenas y pseudo-limos en estos últimos, además de edaforrasgos relícticos tales como fragmentos de cutanes dispersos y abundantes microagregados de suelo retrabajados, revelando la presencia de una paleosuperficie pedosedimentaria en la base de los perfiles. El pedosedimento presenta una mayor proporción de minerales interestratificados con dominancia de esmectita y un incremento de la susceptibilidad magnética respecto a los horizontes sobreyacentes. Su origen podría vincularse a la erosión de suelos preexistentes, proceso controlado por la dinámica tectónica y los cambios climáticos ocurridos en el Pleistoceno. Por otro lado, la similitud composicional determinada para los horizontes superficiales, sugiere que éstos podrían derivar de la acumulación de sedimentos provenientes de la erosión eólica de los cauces fluviales durante un ciclo árido del Holoceno. Luego, en un período reciente más húmedo habría tenido lugar la pedogénesis de estos depósitos. Estas interpretaciones permitirían vincular los ciclos climáticos, con los procesos tectónicos, sedimentarios y pedológicos ocurridos en el sector noroccidental de la cuenca.

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Este artigo descreve as origens, o desenvolvimento e as características da escola de pensamento em morfologia urbana construída a partir do trabalho de M. R. G. Conzen. Depois de se considerarem as influências iniciais de Schlüter e Geisler, é dada atenção aos conceitos desenvolvidos por Conzen – o ciclo da parcela burguesa, a cintura periférica, o quadro morfológico e a região morfológica. Na segunda parte do artigo apresentam-se três exemplos de investigação construídos sobre as fundações lançadas por Conzen, nomeadamente a ‘micromorfologia’, a relação entre períodos morfológicos e processo tipológico, e a ligação entre tomada de decisão e forma urbana.

Geoarchaeological studies with microscopic analysis have been crucial for the verification of soils modified by human action. Micromorphology in Brazil has been used at sites, shell mounds and sambaquis in the south and southeast of the country, in rocky shelters in the Lagoa Santa region (Minas Gerais) and at «Terra Preta» sites in Amazonas and Acre states. So-called anthropic soils play a decisive role in the processes of addition and movement of organic, mineral residues and soil management practices. To identify and interpret the various types of human marks and activities on the ground, it is important to first understand how these changes occur. In principle, human-induced soil disturbances can be caused by processes of adding materials to the soil and these are identified in the micromorphological reading of thin sections. The archaeological sites of potters are located in the Araguaia river basin. Potters settlements in Goiás state were studied in order to identify when and how these groups were implemented in the central region of the country. These studies mention the existence of a darkened soil in the sites that had not been studied by micromorphological investigations until now. The relationship between the characteristics of the Cerrado biome, with its high acidity indexes, and human occupation in a given area is important to understand the taphonomy of the soil. The use of micromorphology demonstrated that even in acidic environments, it is possible to observe post-deposition alterations, microstratigraphic events, microscopic fragments of carbon, bones, various minerals, such as calcium, phosphorous, organic compounds, and ceramic microfragments, all related to anthropic activities from the potter sites. [ABSTRACT FROM AUTHOR]

A morphometric study was carried out to delimit the species of genus Anthoxanthum native to Chile, using 261 herbarium specimens. Through uni and multivariate statistical analyzes based on morphological and anatomical characters, together with the micromorphological study of the abaxial epidermis of the lemma and adaxial epidermis of the leaves, seen under a scanning electron microscope, it was possible to circumscribe six of the nine species described: Anthoxanthum juncifolium, A. moorei, A. pusillum, A. redolens, A. spicatum and A. utriculatum. New combinations are established for Hierochloe moorei and H. quebrada under Anthoxanthum. Anthoxanthum altissimum and A. gunckelii are treated as varieties within A. utriculatum and A. redolens, respectively. Hierochloe sorianoi is treated as synonym of A. redolens var. redolens. A key for the identification of the taxa, maps, distribution data, and morphometric descriptions of the vegetative and reproductive parts of the epidermis in surface view and the cross section of the leaf for each taxon are included. [ABSTRACT FROM AUTHOR]

The genesis and evolution of a soil transect was studied from the western Humid Region to the eastern Semi-Arid Region in the Tucuman's plain. The method of alteration balances, micromorphological techniques and chemical analysis, in total soil and in volcanic glass, was used. It has been found that in the paleosols and recent soils of the Humid Region, there is a continuous and progressive loss of matter from the base to the top of the soils, associated with neoformation of clay and loss of bases, iron and aluminum. The micromorphological study also suggests, a variable sedimentation rate with pedogenesis. These characteristics define a subtractive-redistributive pedogenesis in the paleosols, and an additive-redistributive pedogenesis in the current soils of this region, in which the clay iluviation is the predominant pedogenetic process. In the Semi-Arid Region the alteration balance indicates neoformation of clay, despite the scarce mineral alteration, along with an accumulation of soluble salts, iron and aluminum, which would originate in the alteration of the volcanic glass as indicated by the microprobe analysis. In this region, the pedogenesis is additive-conservative and the predominant pedogenetic process the calcification or isohumism. The analysis clearly shows that the differences in the neoformation of clays can be attributed, both in paleosols and recent soils, to the rainfall gradient that is registered in the Tucuman plain, from the Western Humid Region to the Eastern Semi-Arid Region. [ABSTRACT FROM AUTHOR]

The Tlajinga Barrio is a domestic area situated in the south of Teotihuacan, Estado de México, where preserves original surface materials as well as buried archaeological structures are preserved. Original soil particles mixed with archaeological materials such as stone, stucco, ceramics, and mural fragments enrich the soil mainly with calcium carbonate, contributing to the increase in reflectance in different areas of the terrain, mainly in nearby areas where there were archaeological structures. This is recorded from a synoptic level by the modern remote sensors, with higher spectral, spatial, and radiometric resolution, correlating it to a smaller scale with soil micromorphology analysis. In this way, some minerals present in the floors and walls were identified, mainly the archaeological stucco now transformed into small particles of calcium carbonate. X-ray fluorescence (XFRF) and X-ray diffraction (XRD) complemented the results of remote sensing, spectrometry and micromorphology, identifying the elemental composition of soil particles and associated minerals, mainly calcium carbonate, that were used live in coatings on floors and buildings during the Teoti huacan era. [ABSTRACT FROM AUTHOR]

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Copyright of Terra Latinoamericana is the property of Sociedad Mexicana de la Ciencia del Suelo A.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La clasificación genérica de varios miembros de la tribu Gnaphalieae (Compositae) y en particular la delimitación genérica del antiguo género Gnaphalium ha sido problemática durante mucho tiempo. El género Pseudognaphalium fue escindido de Gnaphalium por su morfología lo que después fue apoyado por filogenias moleculares. Sin embargo, la identidad genérica de algunas especies todavía es dudosa. Aquí aportamos un estudio morfológico de Pseudognaphalium aldunateoides, que es comparado con las especies tipo de los géneros Gnaphalium (Gnaphalium uliginosum) y Pseudognaphalium (Gnaphalium oxyphyllum). También hemos incluido estas tres especies en filogenias moleculares de la tribu Gnaphalieae basadas en ADN ribosómico nuclear y ADN cloroplástico. Nuestros resultados muestran que P. aldunateoides tiene el vilano dimórfico, carácter que no está presente en el género Pseudognaphalium pero que, sin embargo, es característico del género Gnaphalium. Además, su estereoma muestra características intermedias entre el estereoma no dividido típico del género Gnaphalium y el estereoma fenestrado típico del género Pseudognaphalium. En ambas filogenias, P. aldunateoides se sitúa dentro del clado Gnaphalium s. str., no próximamente emparentado con Pseudognaphalium. Con todas estas evidencias concluimos que P. aldunateoides se clasifica correctamente dentro de Gnaphalium.

RESUMO Neossolos Regolíticos no Agreste Meridional de Pernambuco são utilizados para diversas atividades agrícolas, com destaque para a produção de feijão. Há uma variação expressiva na produção dessa cultura, possivelmente associada à presença de lamelas, que conferem comportamento hídrico distinto entre esses solos. Objetivou-se analisar as características macromorfológicas, micromorfológicas e físicas de Neossolos Regolíticos localizados no Agreste Meridional de Pernambuco, com a finalidade de se entender o comportamento hídrico desses solos. Foram coletados e analisados dois perfis de solos localizados nos municípios de Paranatama (P1 - sem lamela) e de São João (P2 - com lamela). Os resultados mostraram que nos atributos morfológicos (cor, textura, estrutura e consistência) não foram observadas diferenças expressivas entre os dois perfis de solos; os atributos físicos (teor de argila, macroporosidade, microporosidade, capacidade de campo e ponto de murcha permanente) apresentaram diferença significativa entre os horizontes dos perfis estudados; a micromorfologia indicou que a maior retenção de água no P2 é consequência da presença de zonas com empacotamento mais denso de seus componentes (empacotamento aglomerático) e expressividade das pontes de argila; e sugere-se adoção do termo “lamélico” pelo atual Sistema Brasileiro de Classificação de Solos (em 4º nível categórico) para diferenciação dos perfis estudados.

The Yalahau region of northern Quintana Roo, Mexico, contains abundant freshwater wetlands and a history of Maya occupation that spans nearly 3000 years. The highest regional population levels occurred during the Late Preclassic period, from ca. 100 BC to AD 350/450. The Maya constructed rock alignments crossing wetland swales, and these have been hypothesized as features used to trap soil and water for production of food and useful biological resources such as periphyton. Paleoenvironmental studies from a wetland in the eastern part of the region suggested that occupation of the Yalahau region, and manipulation of the wetlands, corresponded to a period when the water table was lower than in modern times, creating wetland ecosystems that were most productive for cultivation. This paper presents results that apply this model at the regional scale (in wetlands in other parts of the region). Thirty short soil cores were collected from 12 wetlands across the region. For this project, 5 cores from 4 wetlands were selected for analyses including micromorphology and radiocarbon dating. Thin sections studied under petrographic microscope were used to identify the various types of features present in the core sequences including carbonates, organic matter, shell, pyrite, gypsum, and pore space. In each core, it was possible to distinguish an upper unit dominated by biogenic-micritic carbonate and a lower unit characterized by a variety of unique soil features such as sparitic calcite crystals, pyrite, gypsum, and gleyic properties. Based on this, it is suggested that while modern soil forming processes are fairly uniform across the region and controlled by regular annual flooding (~7 months of >1 m deep flooding each year), in the past (Preclassic period), flooding was less regular and wetland environments were more swampy and varied. Furthermore, it is suggested that the Preclassic depressions encountered by the Maya were a prime agricultural resource that allowed the region to flourish during the Late Preclassic period. However, as flooding became more regular at the end of the Preclassic period, the region was abandoned, only to be reoccupied in the Late Postclassic when wetlands were exploited for aquatic resources rather than for agriculture. [ABSTRACT FROM AUTHOR]

The composition and microfabric of the Av diagnostic surface horizon (crust) and desert varnish of soils formed on various parent materials covering ancient alluvial fans in extremely arid deserts of Central Asia (Trans-Altai Gobi, Mongolia) and North America (Mojave, USA) are analysed. Application of a wide range of methods--morphological and micromorphological descriptions, scanning electron microscopy, electron microprobe analysis and microtomography, together with traditional physicochemical methods-- has shown that desert varnish retains the same composition and relative contents of elements (Fe/Ti and Mn/Ba) independently from the initial composition of parent materials and geographical location of the studied regions. The absolute dominance of isolated closed (vesicular) pores, identified by micromorphology and confirmed by microtomography, can account for specific hydrophysical properties of the crust horizon; that is, low water-holding capacity and permeability. We explain both phenomena of desert pedogenesis--light-coloured crust horizon and dark-coloured desert varnish--the burst of microbiological activity and physicochemical processes after rare but heavy showers during the hot season. The development of iron-depleted zones around pores is considered the evidence of that phenomenon. Consequently, we propose that Mn2+ undergoes mobilization within the crust horizon, followed by its upward migration with capillary and film moisture flows, against the gravity gradient to the surface of desert pavement with its subsequent fixation at the oxygen barrier. The processes of sulphate reduction are indirectly confirmed by the mobilization of Ba2+, which is immobile in the presence of sulphates. These elements (Mn and Ba) accumulate within the lower part of two-layer films. These films are located in microcavities on the upper sides of rock fragments of desert pavements in the studied regions. Films on lower sides of rock fragments and the upper part of those two-layered films are enriched in Fe and Ti, and therefore acquire reddish-brownish colours. Despite its transitory character, the process, which we suggest to call 'cryptosolodization', includes five stages: (1) Fe, Mn and sulphate reduction with mobilization of Ba2+ from BaSO4, (2) precipitation of FeS and migration of Ba2+ and Mn2+ to the stone surface, (3) coprecipitation of Ba and Mn at a combined oxygen-sorption barrier, (4) oxidation of S2- to SO4 2- with mobilization of Ti2+ from TiO2 and (5) oxidation of Ti2+ and Fe2+ and their coprecipitation in the form of oxides/hydroxides TiO2 and Fe(OH)3. [ABSTRACT FROM AUTHOR]

In order to assess the irrigation efficiency under water-limiting conditions, four different treatments of subsurface irrigation of peach trees in a semi-arid Mediterranean climate near Lleida (NE Iberian Peninsula) were tested. The treatments included pressurized air injection, deficit irrigation, full irrigation (as control) and an addition of rice husk around the pipe to improve porosity. Because the latter treatment improved physical conditions and resulted in better tree growth, a micromorphological study was conducted in order to understand the reason for this behaviour. The experiment was carried out in a commercial peach orchard (Prunus persica L.). The soil was a Xeric Torriorthent, with a loam texture, affected by salinity and with low organic matter content. One undisturbed block (30 cm each side) was taken from each treatment, and two vertical thin sections, 5 × 13 cm, including the subsurface pipe, were made. A fluorescent dye was added to the polyester resin to obtain UV light images of the porosity. The pore parameters and the pore size distribution were obtained for each treatment. Strong changes in the pore types of the four treatments are evident in the thin sections. Full and deficit irrigation treatments are characterised by a weakly developed subangular blocky structure, with a vesicular intra-aggregate structure. Deficit irrigation with air injection produced, in its upper part, a structure similar to the full and deficit irrigation treatments. In the surroundings and below the pipe, where the effect of pressurized air was higher, the soil structure is apedal, with vesicles (bubbles), 200 - 500 µm in size. Porosity of the soil modified with rice husk is greater than that of the other three treatments: the 15 - 30 µm porosity fraction is double, and the larger fractions three times that of the other treatments. It contains many oval excrements of mites (probably Oribatidae), 50 - 100 µm in size, associated with moderately decomposed rice husk tissues. We conclude that the modifications around the irrigation pipes that promoted faunal activity are very effective in conveying water to the soil in comparison to that of pressurized air, which only increases vesicular (non connected) porosity. [ABSTRACT FROM AUTHOR]

Diploon is a monospecific genus represented by Diploon cuspidatum, an arboreal species that has morphological characteristics distinct from those of other Sapotaceae species. In this study, Diploon cuspidatum leaves were characterized morphoanatomically in order to reveal additional diagnostic characters of their external morphology of the genus. The Diploon petiole presents shape and arrangement of the vascular system flat-convex, occasionally with one or two accessory bundles, many laticifers, and many prismatic crystals. The midrib is biconvex with a U-shaped cuticle on the abaxial side, and laticifers are associated with the vascular tissues. Mesophyll is dorsiventral, palisade parenchyma has two cell layers, T- and Y-shaped malpighiaceous trichomes are on the abaxial epidermis with a small stalk cell and long arm. The venation pattern is brochidodromous. Intersecondary veins run parallel to the secondary veins, and quaternary veins branch freely. Higher order veins are not present. Morphoanatomical analysis revealed important characteristics that reveal a set of structures common to Sapotaceae, in addition to characters that are important for the recognition and identification of D. cuspidatum. [ABSTRACT FROM AUTHOR]

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A chuva provoca a modificação da estrutura superficial do solo levando ao desenvolvimento de crostas. Este estudo avaliou a dinâmica da formação de crostas superficiais por meio da análise e descrição micromorfológica de lâminas delgadas. O experimento foi conduzido em 2009 e 2010. Em parcelas de 15 x 30 m, foram implantados os diferentes sistemas de preparos do solo: preparo convencional (PC), preparo reduzido (PR) e sem preparo (SP). Dentro das parcelas instalaram-se as microparcelas de 1 x 1m e aplicaram-se diferentes lâminas de chuva simulada (0, 27, 54 e 80 mm) com intensidade de 80 mm h-1. Nas microparcelas, coletou-se uma amostra indeformada em que consistia em um bloco de solo de 0,07 x 0,05 x 0,12 m. Os blocos foram impregnados com resina e após endurecimento e secagem total foram confeccionadas lâminas delgadas (4,5 x 8 cm), descritas, utilizando microscópio óptico. Foi confeccionada uma lâmina delgada para cada chuva (0, 27, 54 e 80 mm) e para cada preparo do solo. Todos os sistemas de preparo avaliados demonstraram presença de crostas; entretanto, o processo de formação das crostas ocorreu com dinâmica diferenciada em cada sistema de preparo. O preparo convencional apresentou formação de crostas a partir de 27 mm de chuva aplicada. O aumento da lâmina de chuva aplicada causou maior degradação da estrutura superficial e maior espessura da camada encrostada. O preparo reduzido e o sistema sem preparo apresentaram condições de superfície irregulares com as chuvas aplicadas, ou seja, não demonstraram modificações constantes da superfície do solo e na formação das crostas, com o aumento da chuva, como constatado no preparo convencional. A análise das lâminas delgadas e a descrição micromorfológica permitiram satisfatória observação e conclusão dos processos e da dinâmica envolvida na formação de crostas.On the soil surface, rainfall modifies the soil surface structure promoting crust development. This study evaluated the dynamics of soil crusting, through description and micromorphological analysis of thin sections in 2009 and 2010. In 15 x 30 m plots, the management systems conventional tillage (CT), reduced tillage (RT) and no tillage (NT) were assessed. Within the plots, 1 x 1 m micro-plots were installed to test different levels of simulated rainfall (0, 27, 54, and 80 mm) at an intensity of 80 mm h-1. From these micro-plots, an undisturbed sample (soil block of 0.07 x 0.05 x 0.12 m) was taken. The blocks were resin-impregnated and after hardening and drying, thin sections (4.5 x 8 cm) were prepared and described using optical microscopy. One thin section was prepared per rainfall level and soil tillage system. Crusts were formed in all tillage systems, however, the process of crust formation was different in each system. Under conventional tillage, crusting was observed after 27 mm rain. A higher rain level increased the degradation of the surface structure and thickness of the crust layer. Under reduced tillage and no-tillage the surface conditions were irregular after the applied rainfall, i.e., the changes in the soil surface and in crust formation were not constant with increasing rain levels, unlike under conventional tillage. The analysis of thin sections and micromorphological description allowed satisfactory conclusions on the processes and dynamics involved in crust formation.

The aim of this paper is to present the termite impact on sampled soil structures during a controlled experiment. The structures used were sampled in a red yellow Latosol. The Cornitermes cumulans colonies were sampled in the same site and were maintained in controlled conditions during 9 months. Two types of structures were tested: dense macrostructures and a strong granular structure sampled in the same site than the colonies. Two replicates of the conceptual termite-structure model were developed. Two pots, one of them with the colony and food material, the second with the same structured material and food, composed each replicate; a tube associated the two pots. Macro and micromorphological descriptions were done, the distribution and localization of galleries were described and compared with those sampled at field. The termites’ colonies maintained their exploring and construction activities, during the period, with some restrictions. In the experimental model with dense macrostructures the activities were important and equivalent in all of the volumes. But, in the experimental model with the strong granular structure the activities were essentially done in the volumes with the mounds. The new structures that were built, soil particles were oriented, and formed rigid walls as they were observed in field samples. C. cumulans colonies explored the volume aleatory in all directions. The new structures showed oriented soil particles, as there were observed in field soil samples, in particular in dense structured galleries walls. Many of the dense structures offered in the pots to the termite activity were completely or partially modified; the dense structure organic matter concentration were increase in the structures sampled in deep soil horizons. It was clear that the termites transformed structures offered, and that there created new microstructures and aggregates. O objetivo deste trabalho foi avaliar o comportamento de térmitas em estruturas oriundas de um Latossolo Vermelho Amarelo. Ninhos em atividade de Cornitermes cumulans (Isoptera, Nasutitermitinae) foram coletados a campo e mantidos em vasos em casa de vegetação por nove meses. As estruturas utilizadas no experimento foram macroestruturas densas e estrutura granular, ambas amostradas no mesmo solo que as colônias. O experimento foi realizado com duas repetições para cada estrutura, sendo cada repetição composta de um vaso com estrutura, ninho e alimento, e um vaso com a mesmo material e alimentação. As estruturas fabricadas pelos térmitas foram descritas macro e micromorfologicamente e comparadas com amostras coletadas no campo, também se verificou a distribuição das galerias. Os térmitas mantiveram as atividades de forrageamento e construção do ninho até o final do experimento, com algumas restrições. Para os vasos com estruturas densas a atividade desenvolveu-se tanto no vaso onde havia o ninho quanto no vaso com alimentação. Em comparação, para os vasos com estrutura granular as construções foram menos desenvolvidas e localizadas nos volumes associados aos ninhos. Nas estruturas construídas, as partículas de solo eram orientadas, formando uma parede rígida, como observado em feições coletadas no campo. As colônias de C. cumulans exploravam o ambiente de forma aleatória em todas as direções, retrabalhando estruturas densas e reagregando as partículas do solo para construção de galerias. Todas as estruturas densas ofertadas às colônias foram parcialmente ou completamente modificadas, e as concentrações de matéria orgânica das estruturas densas oriundas de horizontes profundos do solo foram incrementadas. Os térmitas retrabalham estruturas deixadas por eles ou outros invertebrados do solo, criando microestrutura e re-agregando o solo.

One of the main negative anthropic effects on soil is the formation of crusts, resulting in soil degradation. This process of physical origin reduces soil water infiltration, causing increased runoff and consequently soil losses, water erosion and/or soil degradation. The study and monitoring of soil crusts is important for soil management and conservation, mainly in tropical regions where research is insufficient to explain how soil crusts are formed and how they evolve. The purpose of this study was to monitor these processes on soils with different particle size distributions. Soil crusts on a sandy/sandy loam Argissolo Vermelho-Amarelo (Typic Hapludult), sandy loam Latossolo Vermelho-Amarelo (Typic Hapludox) and a clayey Nitossolo Vermelho eutroférrico (Rhodic Kandiudalf) were monitored. The soil was sampled and data collected after 0, 3, 5 and 10 rain storms with intensities above 25 mm h-1, from December 2008 to May 2009. Soil chemical and particle size distribution analysis were performed. The changes caused by rainfall were monitored by determining the soil roughness, hydraulic conductivity and soil water retention curves and by micromorphological analysis. Reduced soil roughness and crust formation were observed for all soils during the monitored rainfall events. However, contrary to what was expected according to the literature, crust formation was not always accompanied by reductions in total porosity, hydraulic conductivity and soil water retention.

Os Planossolos assumem, na região do Agreste do Estado de Pernambuco, grande importância econômica, tanto pela sua magnitude de ocupação quanto pela utilização intensiva, especialmente com atividades agropecuárias. Aspectos como dualidade ou retrabalhamento do material de origem e natureza dos processos envolvidos na formação das marcantes diferenciações texturais e nas concentrações de Na e de sais são pontos importantes a serem esclarecidos. Este trabalho teve como objetivo avaliar o processo de pedogênese dos Planossolos no Agreste de Pernambuco, com base nos resultados das análises físicas, químicas, mineralógicas, macromorfológicas e, especialmente, micromorfológicas. Foram estudados três perfis de solos com marcante contraste textural, em trincheiras abertas ao longo de uma topossequência de solos. Realizaram-se análises físicas, químicas, mineralógicas e macro e micromorfológicas. Verificou-se que os solos são autóctones e que os nítidos contrastes texturais, devido à argilização dos horizontes Bt, parecem ser, principalmente, o resultado de uma combinação de processos e não uma simples eluviação-iluviação (lessivagem). Entre esses processos estão incluídos a intemperização de biotitas, com formação in situ de argilas, e as perdas dessa fração, devido a movimentações laterais por arraste mecânico ou dissoluções. A combinação exata desses processos, bem como a acumulação de Na, foi fortemente influenciada pelo posicionamento dos solos no relevo.

Se seleccionaron cuatro perfiles de suelo con distinta clase de drenaje con el objetivo de analizar la intensidad del proceso de hidromorfía, y considerar cuáles cumplen con las condiciones ácuicas. Estos fueron: La Aguadita (Udipsamment típico, térmico, bien drenado), La Fronterita XI (Hapludol típico, franco grueso, illítico, térmico, moderadamente bien drenado), La Fronterita X (Argiudol ácuico, franco fino, illítico, térmico, imperfectamente drenado) y Famaillá (Argiu-dol ácuico, fino, illítico, térmico, imperfectamente drenado). Los suelos muestran condiciones de endosaturación durante seis meses al año, con un ascenso del nivel freático durante verano-otoño y un descenso en invierno-primavera. La intensidad de la reducción se evaluó en base a la distribución de hierro y manganeso secundarios asociados a los rasgos redoximórficos identificados micromorfológicamente. En los perfiles bien drenados y moderadamente bien drenados, los Fe d y Mn d mostraron escasa movilidad con valores entre 0,50-0,80% y 0,03-0,06%, respectivamente, y rasgos redoximórficos de escaso desarrollo con un índice Mn/Fe d < 0,08%. En los perfiles con drenaje imperfecto, el Fe d mostró una comigración junto a la arcilla o una separación de la misma con segregación de Fe d fuera del perfil. El Mnd presentó valores deprimidos (< 0,01-0,06%), con un aumento de 0,20% en BC de La Fronterita X y un índice Mn/Fe d = 0,33 junto a rasgos redox más desarrollados. Este análisis sugiere que la hidromorfía aumenta desde La Fronterita XI con drenaje moderadamente bueno, a La Fronterita X y Famaillá, con drenaje imperfecto. En los dos primeros se expresa en el índice Mn/Fe d y el aumento de rasgos redox en tamaño y abundancia, mientras que en el perfil Famaillá, en los valores promedio deprimidos de Fe d y Mn d y la presencia de rasgos redox. Los perfiles La Fronterita X y Famaillá presentan las mayores condiciones reductoras en el contexto de suelos estudiados y se asumen con condiciones ácuicas.The profiles of four soils with different drainage types were selected in the alluvial plain of Tucumán in order to analyze the intensity of the hydromorphy and detect which of the soils conforms to an aquic conditions. The four types were: La Aguadita (thermic Typic Udipsamment) (well-drained), La Fronterita XI (coarse loamy, illitic, thermic Typic Hapludoll) (moderately well-drained), La Fronterita X (fine loamy, illitic, thermic Aquic Argiudoll) (imperfectly drained), and Famaillá (fine, illitic, thermic Aquic Argiudoll) (imperfectly drained). The soils show endosaturation conditions for six months of the year, with an increase in water level during summer-autumn and a decrease in winter-spring. The degree of reduction was assessed in terms of the distribution of iron and manganese associated with redoximorphic features analyzed on a micromorphological scale. In the well-drained and moderately well-drained profiles, Fe d and Mn d show little mobility, with the respective values ranging from 0.50-0.80% and 0.03-0.06%, Mn d / Fe d

O objetivo deste trabalho foi avaliar o potencial de acúmulo de fluoreto em folhas de boldo-gambá (Plectranthus neochilus) e capim-cidreira (Cymbopogon citratus), determinar o percentual de liberação do poluente por meio da infusão e caracterizar, visual e microscopicamente, os danos foliares causados pelo poluente. Mudas das duas espécies foram submetidas a nevoeiro simulado com fluoreto de potássio. O acúmulo de fluoreto na matéria seca foi mensurado com eletrodo específico em folhas lavadas e não lavadas, infundidas e não infundidas. O percentual de flúor disponibilizado nos chás foi superior para capim-cidreira, embora essa espécie apresente acúmulo de flúor menor que o boldo-gambá. Não foram observados sintomas visuais nas folhas das espécies estudadas, mas ao microscópio eletrônico de varredura, constatou-se a alteração da turgidez das células epidérmicas, ruptura da cutícula e deformação de estômatos e tricomas. O elevado teor de fluoreto nas folhas de C. citratus e P. neochilus e a ausência de sintomas visuais evidenciam que as espécies são tolerantes ao poluente. A lavagem das folhas em água é ineficiente para a remoção do flúor. O acúmulo e a liberação diferenciais de flúor estão relacionados às características morfoanatômicas das espécies analisadas.The objective of this work was to evaluate the fluoride accumulation in leaves of blue coleus (Plectranthus neochilus) and lemongrass (Cymbopogon citratus), the percentage of fluoride released through infusion and to characterize visually and through microscopy the injuries caused by the pollutant. Saplings of the species were subjected to a simulated fog with potassium fluoride. Fluoride accumulation in dry matter was measured by a specific electrode in washed and unwashed leaves, subjected and not subjected to infusion. The percentage of available fluorine in teas was higher for lemongrass leaves, even though this species shows a lower fluorine accumulation than blue coleus. No visible symptoms were observed in leaves of either species, although changes in turgidity of the epidermal cells, cuticle rupture and trichome and stomata deformation were observed through scanning electron microscopy. The high contents of fluoride in leaves of C. citratus and P. neochilus and the absence of visual toxicity symptoms reveal that these species are tolerant to the pollutant. Washing the leaves in water is inefficient to remove fluoride. Differences in accumulation and release of fluorine are related to the morpho-anatomical characteristics of the species studied.

En esta nota, se presentan los resultados preliminares del estudio micromorfológico realizado en el depósito ictiológico que recubre al sambaquí Jabuticabeira II, desarrollados en el marco del proyecto temático interdisciplinario Sambaquis e paisagem. El análisis microestratigráfico permitió identificar procesos pre-depositacionales antrópicos que actuaron en la formación de esta estructura, relacionada con la quema y transporte de material mineral (arenas terrígenas) y residuos orgánicos (carbones) e inorgánicos de origen biológico (huesos, fitolitos, diatomeas, agregados silíceos). Los efectos de las alteraciones post-depositacionales sobre estas partículas pueden observarse a través de trazas de disolución en los huesos y la formación de un material mineral fino de composición fosfática. Esta articulación de evidencias confirma la compleja combinación de actividades y procesos de alteración involucrados en la formación de sitios sambaquís, que transciende antiguas dicotomías funcionales.In this note, preliminary results from the micromorphological study of the fish mound that covers the Jabuticabeira II sambaquí site, developed within the interdisciplinary research project Sambaquis e paisagem, are presented. Microstratigraphic analyses enabled the identification of anthropic pre-depositional processes that participated in the formation of this large structure, related to the burning and transport of mineral and organic material (terrigenous sand and charcoal) and inorganic residues of biological origin (bones, phytoliths, diatoms and siliceous aggregates). The effects of post-depositional alterations over these particles can be observed through dissolution traces in bone and the formation of a fine mineral material of phosphatic composition. The articulation of the evidence confirms the complex combination of activities and alteration processes involved in the formation of sambaquí sites, which transcends traditional functional dichotomies.

Soil pore structure characterization using 2-D image analysis constitutes a simple method to obtain essential information related to soil porosity and pore size distribution (PSD). Such information is important to infer on soil quality, which is related to soil structure and transport processes inside the soil. Most of the time soils are submitted to wetting and drying cycles (W-D), which can cause important changes in soils with damaged structures. This report uses 2-D image analysis to evaluate possible modifications induced by W-D cycles on the structure of damaged soil samples. Samples of three tropical soils (Geric Ferralsol, GF; Eutric Nitosol, EN; and Rhodic Ferralsol, RF) were submitted to three treatments: 0WD, the control treatment in which samples were not submitted to any W-D cycle; 3WD and 9WD with samples submitted to 3 and 9 consecutive W-D cycles, respectively. It was observed that W-D cycles produced significant changes in large irregular pores of the GF and RF soils, and in rounded pores of the EN soil. Nevertheless, important changes in smaller pores (35, 75, and 150 µm) were also observed for all soils. As an overall consideration, it can be said that the use of image analysis helped to explain important changes in soil pore systems (shape, number, and size distribution) as consequence of W-D cycles.A caracterização da estrutura do solo usando a análise de imagens bidimensionais (2-D) constitui um método simples na obtenção de informações essenciais relacionadas com a porosidade do solo e a distribuição do tamanho de poros. Tal informação é importante para obter dados sobre a qualidade do solo, a qual está diretamente ligada à sua estrutura e aos processos de transporte que ocorrem no seu interior. Na maior parte do tempo os solos são submetidos a vários ciclos de umedecimento ("wetting") e secamento ("drying") (W-D) que podem causar importantes mudanças em solos que possuem estruturas danificadas. Neste estudo foi usada a análise de imagens em 2-D na avaliação de possíveis modificações devido a vários ciclos de W-D na estrutura de amostras de solo danificadas.Três solos diferentes em textura (Latossolo vermelho-amarelo distrófico - LVAd; Nitossolo vermelho eutrófico - NVe, Latossolo vermelho distrófico - LVd) foram submetidos a três diferentes tratamentos: 0WD, amostras controle não submetidas a nenhum ciclo de W-D; 3WD e 9WD, amostras submetidas a 3 e 9 ciclos consecutivos de W-D, respectivamente. Foi observado que os ciclos de W-D produziram mudanças significativas nos poros grandes irregulares dos solos LVAd e LVd e nos poros arredondados do NVe. Importantes mudanças nos poros de 35 até 150 µm foram observadas para todos os solos estudados. A partir dos resultados obtidos pode ser dito que o uso da análise de imagens auxiliou com sucesso na explicação de variações no sistema poroso (formato, número e distribuição de tamanho dos poros) devido aos ciclos de W-D para todos os solos analisados.

Este trabalho objetivou caracterizar um sistema de solos, evidenciando a propriedades que possam esclarecer sua dinâmica e contribuir para a definição de critérios que condicionem a aptidão destes solos como receptores de efluentes. Trata-se de uma área experimental de estudos, contígua à Estação de Tratamento de Esgoto do município de Lins (SP), onde o efluente é gerado a partir do tratamento de esgoto por sistema de lagoas de estabilização. Os solos, situados ao longo de uma vertente com ligeira inclinação, foram caracterizados por meio de análises, morfológica, granulométrica, química, mineralógica e micromorfológica, realizadas em amostras coletadas em cinco trincheiras em toposseqüência. Os solos são desenvolvidos a partir dos sedimentos arenosos da Formação Adamantina (Grupo Bauru) e constituem um sistema Latossolo - Argissolo onde a transição Bw - Bt ocorre lateralmente do topo para a base da vertente. Foram identificadas três fases pedogenéticas nesta associação de solos. A primeira, argiluviação e adensamento de partículas, responsável pela formação dos horizontes texturais, foi superposta pelos processos de latossolização e hidromorfismo, atuantes na dinâmica atual destes solos. Análises micromorfológicas mostraram tratar-se de solos com intensa porosidade, caracterizada pelo empilhamento dos grãos do esqueleto quartzoso amplamente predominante e pelo arranjo entre os microagregados granulares. A permeabilidade é ainda favorecida pela intensa ação da mesofauna. Os solos são distróficos e compostos por caulinita e óxidos de Fe na fração argilosa. Por constituírem um sistema frágil, a disposição de quaisquer tipos de resíduos nestes solos requer o monitoramento constante de suas propriedades, tanto para a manutenção, quanto para a recuperação da qualidade desta cobertura pedológica.The purpose of this study was the characterization of a soil system, focused on proprieties that can clarify the dynamics and contribute to the definition of criteria that determine the ability of these soils as recipients of effluents. An experimental study area was used, adjacent to the Sewage Treatment Station of the municipality of Lins (SP), where the sewage is treated in a system of stabilization ponds. The soil samples, taken from five trenches in a toposequence of a slight slope, were characterized in morphological, grain, chemical, mineralogical and micromorphological analyses. The soils had developed from the sandy sediment Adamantina (Group Bauru) and represent a Latosol - Argisol system where the transition Bw - Bt occurs laterally from the top to the bottom of the slope. Three pedogenetic phases were identified in this soil system. The first, clay illuviation and particle compaction, responsible for the formation of textural horizons, was overlayered by processes of latosolization and hydromorphism, which are currently active in these soils. Micromorphological analyses showed that the porosity of these soils is intense, characterized by the grain arrangement of the widely prevalent quartz skeleton and arrangement of the granular microaggregates. The permeability is still favored by the intense action of mesofauna. The soils are dystrophic and composed of kaolinite and iron oxides in the clay fraction. For being a fragile system, any type of waste disposal to the soil requires constant monitoring, both for quality maintenance and recovery of the pedological cover.

Este trabalho apresenta uma análise da morfologia do fruto e da sua superfície em 16 táxons de Cyperus L. subg. Cyperus ocorrentes na Região Sul do Brasil, visando à obtenção de caracteres úteis para a sua diferenciação. Na análise macromorfológica destacam-se caracteres como tamanho, forma e cor dos frutos e características relacionadas à base dos mesmos. Na micromorfologia destacam-se caracteres como a ornamentação da superfície do fruto, a distribuição e forma das células epidérmicas, a altura e os limites das paredes anticlinais, o tipo de corpos silicosos e a presença ou não de conexões entre estes e as paredes anticlinais. São fornecidas tabelas comparativas entre os táxons e discutida a importância diagnóstica dos caracteres analisados. Os resultados obtidos sustentam a separação de espécies já bem diferenciadas pela morfologia externa, porém apresentam uma importância limitada na separação de espécies macromorfologicamente semelhantes. Por outro lado, reforçam a proposição de sinonímias para alguns táxons específicos ou infra-específicos.A morphological analysis of the fruit and its surface was carried out in 16 taxa of Cyperus L. subg. Cyperus from Southern Brazil, aiming to obtain useful characteristics for differentiation. In the macromorphological analysis, characters like size, shape, color and those related to the base of the fruit are especially relevant. In the micromorphological analysis, the most important characters are surface ornamentation, distribution and shape of the epidermal cells, height and limits of the anticlinal walls, type of silica bodies and presence or absence of connections between these and the anticlinal walls. Comparative tables for the taxa are provided and the diagnostic value of each character is discussed. The results support the differentiation of species that can be separated by external morphology, but have limited value in the differentiation of similar species. On the other hand, the results support proposals of synonymy for several taxa at specific or infraspecific levels.

La morfología del polen y las características de las orbículas fueron estudiadas en todas las especies de Oxalis sección Palmatifoliae, endémica del sur de Sudamérica, empleando microscopio óptico (M.O.) y microscopio electrónico de barrido (M.E.B.). Los granos de polen son 3-colpados, de forma prolato esferoidales, oblato esferoidales o esferoidales. La exina es microrreticulada. Lúmen circular a poligonal; disminuyendo de tamaño hacia los polos. Las orbículas están dispersas irregularmente en la superficie interna de las anteras; son generalmente aplanadas, redondeadas o con forma de “dona”, de superficie lisa. La homogeneidad observada en la morfología de granos de polen de las especies de Oxalis sección Palmatifoliae refuerza la hipótesis de su origen monofilético y la variedad de tipos de orbículas podría contribuir a la diferenciación interespecífica.

Se describe una nueva especie silvestre de Opuntia (L.)Mill. (Cactaceae) de frutos comestibles ácidos (xoconostles), conocida localmente como “xoconostle matizado”, basados en micromorfología (areola, espina, glóquida, polen y semilla) y morfología externa. Se compara morfológicamente con otras tres especies silvestres distribuidas en la misma región: O. joconostle, O. oligacantha y O. matudae. Con base en el análisis filogenético de un gene de cloroplasto, un espaciador intergénico de cloroplasto y un marcador nuclear se reconoce a la especie como un grupo monofilético dentro del grupo de Opuntia sensu stricto.

Leaf and petiole anatomy of Pterygota species in Nigeria were studied and their distribution within the area is also reported, following outlined standard protocols. They are chiefly distributed in Southern Nigeria especially in wetter areas. Foliar micro-characters showed that the species are hypostomatic and generally paracytic, more abundant in P. berquaertii, with an average of 115/mm2, than in P. macrocarpa, where it is 59/mm2. Epidermal cells are irregular, rectangular and polygonal. Petiole spherical with uniseriate epidermis; cell distribution ranging from solitary to radial multiples. This study has provided valuable information about these indigenous species. Further systematic studies are vital to understand the number and timing of independent evolution of the species into Nigeria. [ABSTRACT FROM AUTHOR]

Micromorphology and structure in fruits of Bulbostylis (Cyperaceae) and their systematic value in Southern America species. The genus Bulbostylis Kunth includes about 150 species that inhabit tropical and subtropical areas worldwide. In Bulbostylis, as in other kinds of sedges, the exomorphology of fruits is one of the steadiest characters for infrageneric classification. This research was focused on evaluating achene micromorphology in twenty Bulbostylis species of Southern America (Argentina, Chile, Paraguay, Uruguay and Paraná, Santa Catarina and Rio Grande do Sul in Brazil). Based on studies with optical and scanning electron microscopy, several groups are proposed, considering the micromorphology of the achenes and presence and type of silicophytoliths. Chemical microanalysis of fruits with EDX/MEB was also performed. The description system based on exomorphological characters, applicable to fruits and seeds, is updated. [ABSTRACT FROM AUTHOR]