The genera and species of Piperaceae show a considerable structural diversity of leaves and especially stems. This paper presents a comparative morphological and anatomical study of the leaves and stems of three common Brazilian species of this family (Peperomia dahlstedtii C.DC., Ottonia martiana Miq. and Piper diospyrifolium Kunth), the vegetative organs of which have previously been little studied. The collected plant material was fixed in FAA, cut freehand and stained in safranin and astra blue. P. dahlstedtii is an epiphyte and has a herbaceous stem with whorled leaves phyllotaxis and a polystelic structure, a multiseriate adaxial leaf epidermis and calcium oxalate monocrystals in parenchyma and collenchyma petiole cells. O. martiana and P. diospyrifolium showed strong similarities, both being terrestrial plants, with alternate phyllotaxis, stele with medullary bundles and dorsiventral leaves with an epidermis and subepidermic layer. In O. martiana the stomatal complex is staurocytic and presented silica crystal sand in parenchyma petiole and midrib cells. In P. diospyrifolium the stomatal complex is tetracytic and there are calcium oxalate raphide crystals in the parenchyma of the petiole and midrib cells. On the other hand, the three species show some structural likenesses in that all have hypostomatic and dorsiventral leaves, oily cells in petiole and mesophyll, secretory trichomes and an endodermis with Casparian strips.

-(Floral morphology and anatomy of Pilocarpus pennatifolius Lem. (Rutaceae)). Pilocarpus pennatifolius Lem. (Rutaceae) presents actinomorphics, dichlamydeous, nectariferous and monoclinous flowers, disposed in pendulous racemes. The anthesis is basipetal in the inflorescence and it is preferentially nocturne. The flower presents five stamens with tetrasporangiate anthers. The anther wall presents epidermis, endothecium, two middle layers and binucleate tapetum; the connective shows epidermis with stomata. The unipistilate gynoecium and compound by five carpels, which are joined at the base of the ovary and at the style and stigma. The style is short and solid and the stigma presents a papilose epidermis. The hemitropous, bitegmic and crassinucelate ovule presents a hypostasis and an obturator, which arises from funicle. The nectary surrounds completely the ovary base. Each sepal receives three vascular traces and the petals and stamens one trace. Each carpel receives a dorsal vascular bundle and two vascular ventral bundles that maintain their individuality throughout their course.Key words -anatomy, anthesis, flower, Pilocarpus pennatifolius, Rutaceae RESUMO -(Morfologia e anatomia da flor de Pilocarpus pennatifolius Lem. (Rutaceae)). Pilocarpus pennatifolius Lem.(Rutaceae) apresenta flores actinomorfas, diclamídeas, nectaríferas e monoclinas, reunidas em cacho pendente. Apresenta antese basípeta na inflorescência e preferencialmente noturna. A flor possui cinco estames com anteras tetrasporangiadas, cuja parede é constituída de epiderme, endotécio, duas camadas médias e tapete binucleado; o conectivo mostra epiderme estomatífera. O gineceu é unipistilado e composto por cinco carpelos unidos na região basal do ovário e no estilete e estigma. O estilete é curto e sólido e o estigma tem epiderme papilosa. O rudimento seminal (óvulo) é hemítropo, bitegumentado, crassinucelado e provido de hipóstase e possui obturador de origem funicular. O nectário envolve completamente a base do ovário. Cada sépala recebe três traços vasculares e as pétalas e estames apenas um; cada carpelo recebe um feixe vascular dorsal e dois ventrais, que mantêm individualidade em todo seu curso.

RESUMO -(Morfoanatomia e histoquímica de Brosimum gaudichaudii Trécul (Moraceae)). Brosimum gaudichaudii, conhecida como mamacadela, é espécie comum nos cerrados, com grande valor na medicina popular e na indústria de medicamentos. A casca da raiz e do caule é empregada no tratamento do vitiligo, sendo o bergapteno e psoraleno, duas furanocumarinas, responsáveis pela ação farmacológica. Neste trabalho são apresentadas a caracterização morfoanatômica e a histoquímica de órgãos vegetativos de B. gaudichaudii, com informações sobre o embrião e o desenvolvimento pós-seminal. Amostras foram processadas segundo técnicas usuais em anatomia e ultra-estrutura vegetal. O embrião é do tipo total e invaginado, a plântula cripto-hipogéia e o sistema radicular do tirodendro é composto por raiz primária pouco desenvolvida em relação às raízes laterais. Plantas adultas apresentam raízes gemíferas longas, plagiotrópicas originando ramos caulinares aéreos; tais raízes possuem periderme com súber desenvolvido e floema secundário abundante em relação ao xilema, sendo facilmente destacados quando manipulados. O caule jovem e a folha apresentam epiderme unisseriada, grande densidade de tricomas tectores unicelulares e tricomas glandulares. Laticíferos não-articulados ramificados ocorrem em todos os órgãos, podendo invadir os elementos de vaso. Idioblastos fenólicos ocorrem em abundância em todos tecidos e órgãos analisados. O valor das características anatômicas observadas no controle de qualidade da droga é discutido. Palavras-chave:Brosimum gaudichaudii, idioblastos fenólicos, laticíferos, mamacadela, raízes gemíferas ABSTRACT -(Morphoanatomy and histochemistry of the Brosimum gaudichaudii Trécul (Moraceae)). Brosimum gaudichaudii known as "mamacadela" is a common cerrado species with a great importance on medicine folk and in the pharmaceutical industry. The bark of the root and stem is used on the treatment of "vitiligo" being the bergapten and psoralen two furocoumarins responsible for pharmacological activity. This work presents the morphoanatomical and histochemical characterization of the vegetative organs of B. gaudichaudii, with information about its embryo and post-seminal development. Samples were processed by usual techniques of plant anatomy and ultra-structure. The embryo is of the total type and invaginate, the seedling is crypto-hypogeal and the tirodentro's radicular system is composed by primary root that is not always well developed when compared to other roots that probably are derived of the hypocotyl which have greater size. The adult plants present long shoot bud-forming roots and plagiotropics origining with air branch. These roots present a periderm with developed phellem and secondary phloem more developed than xylem, being both easily eminent when manipulated. The stem and the leaf show unisseriate epidermis with a high density of unicellular non-glandular trichomes and glandular trichomes. The laticiferous are branched and non-articulate, occurring at all organs mostly frequently inside of the vessel elem...

Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of the root system reduced. The leaf anatomy of plants grown in solutions containing 75 and 300 µmol L-1 Al differed in few aspects from the control plants. The leaf sheaths of the plants exposed to Al had a uniseriate epidermis coated with a thin cuticle layer, and the cells of both the epidermis and the cortex were less developed. In the vascular bundle, the metaxylem and protoxylem had no secondary walls, and the diameter of both was much smaller than of the control plants.

ABSTRACT

Bee Diversity in Tecoma stans (L.) Kunth (Bignoniaceae): Importance for Pollination and Fruit Production ABSTRACT -Tecoma stans (L.) Kunth is an exotic plant in Brazil, commonly distributed in urban areas, which is considered an invasive species in crop and pasture areas. In this study, the floral biology and the behavior of bees in flowers of T. stans from three urban areas in southeastern Brazil were investigated. In all study sites, T. stans was an important food resource to the Apoidea to 48 species of bees. Centris tarsata Smith and Exomalopsis fulvofasciata Smith (Hymenoptera: Apidae) were the effective pollinators more abundant, while Scaptotrigona depilis Moure (Hymenoptera: Apidae) was the more frequent robber species. The most part of T. stans visitors (87.5%) exploited exclusively nectar, which varied in sugar concentration depending on the day period and flower phase. In all flower stages, higher averages of nectar concentration (26.4% to 32.7%) occurred from 10 am to 2 pm. The presence of osmophore in the petals and protandry were detected. In two urban areas the number of visitors varied significantly during the day. The greatest abundance of pollinators occurred when pollen availability was higher and flowers showed receptive stigma, which could be contributing to the reproductive success of T. stans. The results indicate that the production of fruits increased in plants that received a higher number of effective pollinators.KEY WORDS: Apidae, urban area, floral visitor, effective pollinator RESUMO -Tecoma stans (L.) Kunth é uma espécie vegetal introduzida no Brasil, comumente encontrada em áreas urbanas e considerada invasora de ambientes cultivados e áreas de pastagem. Neste trabalho foram estudados aspectos da biologia foral, diversidade e comportamento de coleta das abelhas em flores de T. stans em três áreas urbanas no Sudeste do Brasil. Nas três áreas, T. stans mostrou-se importante fonte de recursos alimentares utilizados 48 espécies de abelhas. Centris tarsata Smith e Exomalopsis fulvofasciata Smith (Hymenoptera: Apidae) foram os polinizadores efetivos mais abundantes e Scaptotrigona depilis Moure (Hymenoptera: Apidae) a espécie pilhadora mais freqüente. A grande maioria (87,5%) dos visitantes de T. stans coletou exclusivamente néctar, recurso que variou em concentração durante o dia e nas diferentes fases da flor. Em todos os estágios florais, as maiores concentrações médias de néctar ocorreram entre 10:00h e 14:00h. Detectou-se a presença de osmóforos nas pétalas e protandria. Em duas áreas estudadas o número de visitantes variou significativamente durante o dia. A maior abundância de polinizadores ocorreu nos períodos de maior disponibilidade de pólen e estigmas receptivos, fato esse que pode ser determinante para o sucesso reprodutivo de T. stans. Os resultados indicam ainda maior produção de frutos em plantas que receberam o número maior de polinizadores efetivos. PALAVRAS-CHAVE: Apidae, área urbana, visitante floral, polinizador efetivo

-(Morphoanatomy and histochemistry of the reproductive organs from Brosimum gaudichaudii (Moraceae)). Brosimum gaudichaudii Trécul, ordinary known as mama-cadela, is an arboreous species common on Brazilian savannah with a great importance on popular food and medicine. The yellow pulp of its fruit is very appreciated by the children because its like a chewing gum. This work presents the morphoanatomical and histochemistry characterization of the inflorescence, fruit and seed of B. gaudichaudii. The material were processed by anatomical and ultrastructural usual techniques. The inflorescence is capitate, globose, pedunculate, pendent, predominant by pairs on leaf axilla and covered by thickly hairy peltate bracts. Each inflorescence is composed of several male flowers and one female flower. The male flowers are constituted by a stamen involved by bracteoles. The female flower is constituted by a pistil with an inferior ovary with five carpels, nevertheless just one develops. It is common the presence of two ovules on developed locule, however just one will develop on a seed. The ovule is pendulous, hemianatropous and bitegmic only on the micropilar region. The mature fruit shows: the pulp which is to the comestible region and endocarp; in the seeds the tegument is membranaceous and the embryo without secondary endosperm. The parenchymatic tissue of the pulp presents a lot of intercellular spaces replete of aqueous content. The endocarp is sclerified and shows to be well differentiable on mature fruit. The laticiferous are non-articulated branched with thick walls occurring on inflorescence receptaculum, being abundant on peduncle and in the pulp of the mature fruit and embryo. The phenolic idioblasts are distributed in the inflorescence and fruit.Key words -Anatomy, Brosimum gaudichaudii, fruit, inflorescence, morphology, seed RESUMO -(Morfoanatomia e histoquímica de órgãos reprodutivos de Brosimum gaudichaudii (Moraceae)). Brosimum gaudichaudii Trécul, popularmente conhecida como "mama-cadela", é uma espécie arbórea comum nos cerrados brasileiros, de grande importância na alimentação e na medicina popular. A polpa amarela dos frutos é muito apreciada pelas crianças por ser semelhante à goma de mascar. Neste trabalho é apresentada a caracterização morfoanatômica e histoquímica da inflorescência, fruto e semente de B. gaudichaudii. O material foi processado segundo técnicas usuais para estudos anatômicos e ultra-estruturais. As inflorescências são captadas, globosas, pedunculadas, pendentes, predominantemente aos pares nas axilas foliares e recobertas por brácteas peltadas densamente pilosas. Cada inflorescência é composta por várias flores masculinas e uma flor feminina. As flores masculinas são constituídas por um estame envolvido por bractéolas. A flor feminina é constituída por um pistilo com ovário ínfero penta-carpelar, entretanto um só lóculo se desenvolve. É comum a presença de dois óvulos no lóculo desenvolvido; entretanto somente um óvulo se desenvolve em semente. O óvulo é pêndulo, hemianátropo...

Studies on the morphology and anatomy of the flowe r and anthesis of Metrodorea nigra