Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological effects, such as anti-microbial, anti-inflammatory and anticancer. Shoot apices of Baccharis dracunculifolia (alecrim plant, Asteraceae) have been pointed out as sources of resin for green propolis. The present work aimed (i) to observe the collecting behavior of bees, (ii) to test the efficacy of histological analysis in studies of propolis botanical origin and (iii) to compare the chemistries of alecrim apices, resin masses and green propolis. Bee behavior was observed, and resin and propolis were microscopically analyzed by inclusion in methacrylate. Ethanol extracts of shoot apices, resin and propolis were analyzed by gas chromatography/mass spectroscopy. Bees cut small fragments from alecrim apices, manipulate and place the resulting mass in the corbiculae. Fragments were detected in propolis and identified as alecrim vestiges by detection of alecrim structures. Prenylated and non-prenylated phenylpropanoids, terpenoids and compounds from other classes were identified. Compounds so far unreported for propolis were identified, including anthracene derivatives. Some compounds were found in propolis and resin mass, but not in shoot apices. Differences were detected between male and female apices and, among apices, resin and propolis. Alecrim apices are resin sources for green propolis. Chemical composition of alecrim apices seems to vary independently of season and phenology. Probably, green propolis composition is more complex and unpredictable than previously assumed.

This work describes the leaf anatomy of 16 species belonging to three genera of the Malpighiaceae family found in the Cerrado (Minas Gerais State, Brazil). The scope of this study was to support the generic delimitation by contributing to the identification of the species and constructing a dichotomous identification key that includes anatomical characters. The taxonomic characters that were considered to be the most important and used in the identification key for the studied Malpighiaceae species were as follows: the presence and location of glands; presence of phloem in the medullary region of the midrib; mesophyll type; presence and type of trichomes; and presence, quantity, and disposition of accessory bundles in the petiole. It was also possible to indicate promising characters for future taxonomic and phylogenetic studies in the Malpighiaceae family, especially for the Banisteriopsis, Byrsonima, and Heteropterys genera.

RESUMO -A anatomia da folha, de colmo e do rizoma de Digitaria insularis foi investigada, visando identificar características que possam estar relacionadas à sua tolerância ao glyphosate. Sementes e rizomas de plantas adultas foram coletadas em campo, em área de plantio direto, onde o herbicida glyphosate vem sendo utilizado repetidamente há vários anos. As plantas provenientes dessas sementes e desses rizomas foram cultivadas em vasos com capacidade de 3 L, contendo solo de textura média, em casa de vegetação. Quando as plantas atingiram o estádio fenológico de pré-florescimento, foram coletadas três folhas totalmente expandidas por planta, entre o terceiro e o quinto nó. Simultaneamente, coletaram-se fragmentos dos rizomas e os entrenós recobertos pelas bainhas das folhas amostradas. As amostras foram fixadas em FAA 50 e estocadas em etanol, para obtenção de cortes histológicos e montagem das lâminas, conforme metodologia usual. Para obtenção do índice estomático e da densidade estomática nas superfícies da epiderme, amostras das folhas foram diafanizadas, conforme método utilizado usualmente. Verificou-se que plantas provenientes de rizomas apresentavam maior índice estomático e maior número de estômatos por mm 2 , maior espessura na epiderme das faces adaxial e abaxial e maior espessura da lâmina foliar. Foi observada coloração intensa nos rizomas submetidos ao Lugol, indicando presença de grande quantidade de amido, independentemente da origem do material.Palavras-chave: capim-amargoso, anatomia, glyphosate, amido.ABSTRACT -The anatomy of the leaf, stem and rhizome of Digitaria insularis was studied, evaluating characteristics that could be related to its tolerance to glyphosate. Seeds and rhizomes of adult plants were collected in the field, area of no-till system, where the herbicide glyphosate had been repeatedly used for several years. The plants derived from these seeds and rhizomes were cultivated in 0.003 m 3 vases, containing soil, under a greenhouse conditions. When the plants reached the preflowering stage, three totally expanded leaves were collected per plant, between the third and fifth nodes. Fragments of the internodes covered by the sheaths of the sampled leaves were collected together with the rhizomes. The samples were fixed in FAA 50 and embedded in ethanol to obtain histological sections and mount the slider, according to the methodology. Leaf samples were diaphanized, following the usual methodology, to obtain the stomatal index and stomatal density at the epidermal surfaces. Plants derived from rhizomes had higher stomatal index and larger number of stomata per mm 2 , thicker adaxial and abaxial epidermis faces and thicker leaf lamina. The intense coloration in the rhizomes treated with lugol indicated the presence of a great amount of starch, regardless of the origin of the material.

Colleters are secretory structures that occur in vegetative or reproductive shoot apices of many botanical families. However, in the order Myrtales, reports of colleters have considered only external morphology. We therefore evaluated apical meristems of 52 species belonging to 17 genera from seven tribes of subfamily Myrtoideae (Myrtaceae), so as to analyse the incidence and morphological types of colleters. The samples were fixed for light and scanning electron microscopy. Histochemical tests were carried out on fresh and methacrylate-embedded material. Proteins of the colleter secretions were analysed by SDS-PAGE. We have classified and described the following three new colleter types: petaloid, conic and euryform. None of the species contained all three colleter types. The petaloid colleters were present in three tribes (Syzygieae, Melaleuceae and Lophostemoneae). The conic colleters were observed in three tribes (Leptospermeae, Myrteae and Melaleuceae) and the euryform type occurred in five tribes (Leptospermeae, Syncarpieae, Myrteae, Syzygieae and Melaleuceae). In the tribe Eucalypteae, we found no evidence of colleters. The presence of mucilaginous secretion that defines colleters was confirmed by histochemical tests, and no proteins were found in the secretion. The colleters in Myrtoideae may help clarify the phylogenetic relationships of the Myrtaceae family.

This study revealed a high diversity of secretory structures, including novel ones, in one of the largest clades of Euphorbiaceae. Our results are promising for investigations on the anatomical and ecophysiological bases of species diversification within Euphorbiaceae.

RESUMO -(Estratégias anatômicas foliares de treze espécies de Orchidaceae ocorrentes em um campo de altitude no Parque Estadual da Serra do Brigadeiro (PESB) -MG, Brasil). O estudo objetivou caracterizar, anatomicamente, as folhas de Orchidaceae ocorrentes em um campo de altitude (PESB), identificando caracteres anatômicos úteis na interpretação das estratégias adaptativas. As treze espécies estudadas vivem em condições ambientais extremas tendo sido estudados apenas indivíduos terrestres, exceto Pleurothallis teres Lindl. espécie exclusivamente rupícola. Avaliando os caracteres anatômicos adaptativos, dois grupos podem ser distinguidos, os das espécies perenes (Epidendrum secundum Jacq., Epidendrum xanthinum Lindl., Oncidium barbaceniae Lindl., Oncidium blancheti Rchb. F., Pleurothallis prolifera Lindl., Pleurothallis teres Lindl., Zygopetalum brackypetalum Lindl. e Zygopetalum mackaii Hook.) e os das espécies com redução das partes aéreas no período seco (Cleistes gracilis Schdl., Habenaria hydrophila Barb. Rodr., Habenaria janeirensis Kraenzl, Habenaria macronectar Hoehne e Prescottia montana Barb. Rodr.). As espécies perenes apresentam caracteres xeromórficos: folhas coriáceas ou coriáceas suculentas, cutícula espessa e estriada, hipoderme, grupos de fibras esparsas no mesofilo homogêneo, parênquima aqüífero com espessamento em barras ou espiralados nas paredes, idioblastos de ráfides e feixes vasculares colaterais circundados e com calotas de fibras. Nas espécies com redução das partes aéreas ocorrem investimentos diferenciados e os caracteres xeromórficos não são acentuados. As folhas são delgadas, com células epidérmicas adaxiais altas sendo a cutícula delgada geralmente desprovida de estriamentos e a presença de idioblastos de ráfides freqüentes no mesofilo. Não ocorre hipoderme e os feixes vasculares são reduzidos e sem associações com fibras. Palavras-chave:Orchidaceae, anatomia, estratégias adaptativas, folha, campo de altitude ABSTRACT -(Strategies anatomy from thirteen Orchidaceae species occurring in a "high altitude grasslands" in the State Park of Serra do Brigadeiro (PESB) -Minas Gerais State, Brazil). The purpose of this work was to characterize the leaf anatomy of thirteen Orchidaceae species in a "high altitude grasslands", located at State Park of Serra do Brigadeiro, and identify anatomical characteristics helpful to the interpretation of adaptative strategies of these species. The species studied were all terrestrial plants except Pleurothallis teres Lindl. that occurring on granitic rock living in extremely conditions. Observations made in adaptative anatomic features showed that two different groups can be easily distinguished: perennial species (Epidendrum secundum Jacq., Epidendrum xanthinum Lindl., Oncidium barbaceniae Lindl., Oncidium blancheti Rchb. F., Pleurothallis prolifera Lindl., Pleurothallis teres Lindl., Zygopetalum brackypetalum Lindl. and Zygopetalum mackaii Hook.), and species with reduced aerial parts during drought periods (Cleistes gracilis Schdl., Habenaria hydrophila...

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