Abstract Bauhinia monandra Kurz (Fabaceae) is an ornamental leguminous tree from Africa. Its leaf has been proven to be hypoglycaemic, and are a source of lecithin BmoLL, providing this species with great medicinal potential. Curiously, there are no reports of the anatomical description of the leaf of this species. The present work aimed at describing the leaf anatomy of B. monandra, and make histochemical inferences. To this end, anatomical procedures in light and scanning electron microscopy were performed from different parts of the leaves of plants growing in the state of Bahia, Brazil. The leaf is amphistomatous. It possesses papillate epidermis, nonglandular and navicular trichomes, and the mesophyll is dorsiventral. The central vein is distinct from the others of the first degree. The first, second, and third-degree veins possess thick fibre bundles with associated monocrystals. The other veins are a little fibrous and excessively reduced. The petiole vascularisation consists of circularly arranged collateral bundles, plus two accessory bundles. The pulvinus have a wide parenchymatic cortex with abundant druses and vascularisation restricted to the central region, surrounded by a crystalline sheath and by a starch sheath. The motile cushion has the vascular bundles arranged in series. Associated with the phloem from the pulvinus vascular bundles and the motile apparatus, occur non-lignified septate fibres that confer flexibility to these organs. The absence of lateral projections and the arrangement of vascular bundles in the petiole was the most distinctive anatomical features and of the greatest taxonomic potential observed in the leaf of B. monandra.

RESUMO A resina glicol-metacrilato é um meio de inclusão de grande conveniência no estudo histológico e citológico, nos mais variados tipos de tecido. Oferece excelente suporte mecânico no seccionamento de amostras, mesmo nas com grandes diferenças de dureza, e permite uma ampla gama de colorações e testes histoquímicos. Durante a etapa de infiltração, em especial quando realizada durante vários dias, pode ocorrer a polimerização acidental da resina, o que leva à impressão de que a amostra foi perdida. O presente trabalho objetivou elaborar uma técnica de correção de posição de amostras de tecidos vegetais em blocos de resina glicol-metacrilato acidentalmente polimerizada. Para este fim, os blocos de resina acidentalmente polimerizada contendo amostras vegetais foram desbastados e reincluídos adequadamente. Os resultados foram satisfatórios, obtendo-se cortes de três micrômetros de espessura com facilidade e qualidade.

ABSTRACT Glycol methacrylate resin is a very convenient medium used for inclusions of various types of tissue for histological and cytological studies. It provides excellent mechanical support in the sectioning of samples, even the ones with big differences in hardness. Additionally, it allows a large range of stain techniques and histochemical tests. During the infiltration stage, especially if it lasts for several days, the resin may be accidentally polymerized, which may give the impression that the sample has been lost. The present work aims to provide a technique for correcting the position of plant tissues samples embedded in accidentally polymerized glycol methacrylate resin. For this purpose, blocks of resin accidentally polymerized containing plant samples were trimmed and reshaped appropriately. The results were satisfactory and it was possible to obtain good sections of three micrometers thick.

ABSTRACT The present work presents an optimized form for distributing serial sections in a glycol methacrylate slide set. This consists of filling the first row with sections from each slide, thus proceeding in the same way with the other rows. Therefore each slide will contain sections of three distinct sample segments.

O presente trabalho apresenta um equipamento feito com material barato, destinado à inclusão de material botânico em parafina sob vácuo, utilizando-se uma estufa e uma bomba de vácuo. O equipamento foi testado utilizando-se amostras de botão floral de Rodriguezia venusta (Orchidaceae) incluídas em parafina, das quais metade foi submetida ao vácuo pelo equipamento durante a infiltração. O material foi seccionado em micrótomo rotativo, obtendo-se séries completas de cortes de boa qualidade das amostras submetidas ao vácuo. O controle foi de difícil microtomia, obtendo-se cortes danificados pela presença de bolhas de ar, dificultando assim a formação de fitas. Estes resultados comprovam a eficácia do equipamento proposto, sendo este uma solução prática, barata e portátil para laboratórios em início de estruturação.

The present work describes an equipment constructed using inexpensive material for embedding the plant material in the paraffin under the vacuum, using an oven and a vacuum pump. The equipment was tested using the samples of Rodriguezia venusta (Orchidaceae) buds embedded in paraffin, where half of the samples were submitted to the vacuum by the equipment during the embedding. The material was sectioned with a rotary microtome, obtaining full series of quality sections. The control was hard to section with the microtome, obtaining damaged sections due the air bubbles, making the ribbon formation difficult. These results proved the effectiveness of the equipment, making it a practical, inexpensive and more portable solution for newly established laboratories.