Resumo: Estudos de germinação de sementes em espécies de Eugenia após fracionamento de embriões demonstraram que as células dos cotilédones têm grande capacidade de desdiferenciação e consequente produção de raízes. No entanto, não há informações sobre a origem dessas novas raízes. Assim, o objetivo deste estudo foi caracterizar anatomicamente as regiões dos cotilédones de sementes de cinco espécies de Eugenia para elucidar o tecido que origina tais raízes. As sementes foram seccionadas na região do hilo e imediatamente colocadas para germinar. Assim que as frações desenvolveram raízes, elas foram fixadas e processadas com as técnicas usuais de microscopia de luz. As raízes adventícias originaram-se apenas quando a semente foi fracionada, nunca ocorrendo espontaneamente em sementes não danificadas. Raízes adventícias foram formadas a partir de células do parênquima perivascular, localizadas próximas à região lesada dos cotilédones. Essas células se dividiram periclinalmente e proliferaram, dando origem a um meristema radicular. Dessa forma, as novas mudas provavelmente têm genoma diferente da planta mãe, mas seriam idênticas ao embrião resultante da fecundação.

Abstract: Studies on seed germination in Eugenia species after embryo fractionation have demonstrated that cotyledon cells have capacity for de-differentiation and consequent production of roots. However, there is no information about the origin of those new roots. Thus, the aim of this study was to characterize anatomically the cotyledon regions of seeds of five species of Eugenia to elucidate the tissue that originates such roots. Seeds were sectioned across the hillum region and immediately placed to germinate. As soon as the fractions of these cut seeds develop roots they were fixed and processed to the usual techniques for light microscopy. The adventitious roots originated only when the seed was fractioned, never occurring spontaneously in uninjured seeds. Adventitious roots were formed from perivascular parenchyma cells, located close to the injured region of the cotyledons. These cells divided periclinally and proliferated, giving rise to a root meristem. Therefore, new seedlings probably have a different genome than the mother plant, but they would be identical to the embryo that was a result of fertilization.

ABSTRACT Glandular trichomes are epidermal structures that produce, store and release a variety of chemical compounds. Their high morphological diversity allows their taxonomic use at various levels. Therefore, their description and standardization of terminology become challenging. Cannabaceae is a well known family of Urticalean Rosids because of the presence of cannabinoid-secreting trichomes in Cannabis sativa. Other Urticalean Rosid families (Moraceae, Ulmaceae and Urticaceae) are neglected in this regard. Thus, the morphology and distribution of glandular trichomes were studied in Cannabaceae and Ulmaceae species and compared with published data for Moraceae and Urticaceae. Surface and anatomical analyses were performed on vegetative and floral organs. Urticalean Rosids show at least 15 types of glandular trichomes, 12 of them capitate and three filiform. In particular, Trema micrantha, a Cannabaceae species, has six different types. A trichome with biseriate stalk and pluricellular head, found in Trema micrantha and Pteroceltis tatarinowii, was not previously reported. Glandular trichomes are widely distributed in the plant body, which may be related to protection against herbivory. The greatest difficulty was the large quantity of terms and the lack of morphological details of the glandular trichomes in previous studies. A standardization of the terminology of glandular trichomes was therefore proposed.

ABSTRACT In 2019, the atmospheric CO2 concentration exceeded the 415 ppm milestone for the first time in the human history. According to projections of the Intergovernmental Panel on Climate Change (IPCC), CO2 levels will continue to rise in the future, potentially affecting all living organisms. Plants with C3 metabolism may benefit from rising CO2 levels because the significant losses of photosynthesis, driven by photorespiration could be diminished under this scenario. This study addressed the anatomical changes in the stems of young Eucalyptus urophylla plants induced through cultivation in elevated CO2 (eCO2). Plants cultivated under eCO2 showed increased stem diameter (i.e., radial width of the secondary xylem, secondary phloem and cortex tissues). Periodic acid-Schiff (PAS)/Toluidine Blue staining suggested a decrease in the lignification content in the newly formed tissues of eCO2 stimulated plants. Levels of caffeate/5-hydroxyferulate O-methyltransferase form 1 (COMT1), a lignin biosynthesis specific proteoform, were significantly reduced in stem sections, supporting our findings: eCO2 induces plant growth, but reduces lignified tissues.

ABSTRACT Floral secretory structures are usually associated with the attraction of pollinators, but may also play an important role in the mechanisms of plant protection. This study aimed to show the diversity of secretory structures present in the developing flowers of 15 legume species belonging to different clades and to associate them with functions other than the pollinator attraction. Buds, flowers and developing axis of inflorescence were processed for surface, histological, and ultrastructural analyses. The species investigated displayed a wide diversity of secretory structures in developing flowers such as phenolic cells and/or tissues, mucilaginous cells, secretory cavities, secretory trichomes and colleters. Each type of secretory structure exhibited variation in morphology and location in the flower and/or axis of inflorescence depending on the species. Special mucilage cells, secretory cavities, secretory trichomes and colleters have great potential for comparative morphological studies due to their diversity of forms or restricted occurrence to certain taxa, contributing to a more robust morphological data base for the new clades emerging in Leguminosae. The scarcity of reports about floral secretory structures of Leguminosae seems to be more related to deficient sampling than to the absence of such structures in the group, which highlights the need for further investigation.

ABSTRACT Dipteryx, Pterodon and Taralea are legume genera known for secreting oils, produced in secretory canals and cavities, with medicinal properties. We analyzed the distribution, morphology and histochemistry of these glands in leaves and stems of Dipteryx alata, Pterodon pubescens and Taralea oppositifolia, three Neotropical species, using standard techniques for anatomy and histochemistry. Secretory spaces, i.e. secretory cavities and canals, exhibited a wide lumen and a single layer of epithelium. Digitiform epithelial cells, forming trabeculae protruding into the lumen, were seen in all three species. Secretory cavities with a rounded or oval lumen and secretory canals with an elongated lumen in longitudinal sections were found only in T. oppositifolia. In D. alata and P. pubescens, only secretory cavities were found. In P. pubescens, secretory cavities occurred in the leaf blade margin. In T. oppositifolia, secretory spaces were much more numerous than in the other two species. Terpenes, total lipids, phenolic compounds, alkaloids and polysaccharides were detected in the secretory spaces of the three species. The abundance of secretory spaces, the presence of canals in T. oppositifolia and the position of cavities in P. pubescens are features with potential diagnostic value for their respective genera.

ABSTRACT This study aimed to obtain new information about the distribution, morphology and content of secretory trichomes present in the vegetative and reproductive organs of four species of Moraceae: Artocarpus heterophyllus, Dorstenia cayapia, Maclura tinctoria and Sorocea bonplandii. Stem, leaf, flower and inflorescence samples were processed for scanning electron and light microscopy. The species have secretory trichomes on the leaf blade, petiole and stem and also on the inflorescence and flowers of D. cayapia and S. bonplandii and on the peduncle of the inflorescence in A. heterophyllus. These trichomes are of the capitate type in all species, but A. heterophyllus also possess peltate secretory trichomes. Both trichome types exhibit a multicellular head and a unicellular peduncle. Peduncle size and head cell number varies according to species. Peltate trichomes located in depressions were found only in species of Artocarpus, and so should be of diagnostic value for the genus. In all species the trichomes secrete polysaccharides, alkaloids and lipids; phenolic compounds occur in A. heterophyllus and M. tinctoria trichomes. These trichomes probably act in the protection against herbivores, pathogens, desiccation and/ or UV radiation. Moreover, the trichomes found in the inflorescence of D. cayapia may exert a function in pollen grain adhesion.

RESUMO A uvaieira (Eugenia pyriformis Cambess.), espécie arbórea e frutífera, com potencial farmacológico e gastronômico, apresenta sementes sensíveis à dessecação. O objetivo deste trabalho foi analisar se o grau de tolerância à dessecação de sementes de uvaieira depende do grau de maturidade das sementes no momento de sua dispersão. Este, por sua vez, depende das condições ambientais nas quais as sementes se desenvolvem, incluindo-se o acúmulo de graus-dia e a chuva acumulada no período. As sementes foram coletadas de frutos maduros de matrizes localizadas em São Paulo e Minas Gerais, submetidas à secagem e analisadas quanto ao teor de água e germinação. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 20 x 3 (origem do material x níveis de secagem). O grau de tolerância à dessecação difere entre as regiões e épocas de coleta, inclusive dentro da mesma matriz, quando as sementes são coletadas em anos distintos. As condições hídricas e térmicas do ambiente, durante o desenvolvimento das sementes, condicionam o ciclo de maturação, a qualidade fisiológica e a aquisição da tolerância à dessecação. A tolerância à dessecação de sementes de uvaieira depende da maturidade fisiológica das sementes no momento de sua dispersão, a qual está associada às condições ambientais.

ABSTRACT Eugenia pyriformis Cambess., known locally as uvaieira, a species of fruit-bearing tree with both pharmacological and gastronomic potential, has seeds which are sensitive to desiccation. The aim of this study was to analyse whether the degree of tolerance to desiccation of uvaieira seeds depends on the stage of maturation of the seeds at shedding. This, in turn, depends on the environmental conditions in which the seeds develop, including the accumulation of degree-days and rainfall in the period. Seeds were collected from the ripe fruit of parent plants located in the states of São Paulo and Minas Gerais, Brazil, submitted to drying and analysed for water content and germination. A completely randomised design was used in a 20 x 3 factorial scheme (source of material x level of drying). The degree of desiccation tolerance differs between region and period of collection, even for the same parent plant when the seeds are collected in different years. The water and thermal conditions of the environment during seed development modify the maturation cycle, the physiological quality and the acquisition of desiccation tolerance. In uvaieira seeds, desiccation tolerance depends on the physiological maturity of the seeds at the time of dispersal, which is associated with the environmental conditions.

O nome popular "anileira" designa Indigofera anil L., I. suffruticosa Mill. e I. truxillensis Kunth, muito semelhantes quanto à morfologia externa. Este trabalho teve por objetivo avaliar se caracteres da semente e plântula apresentavam valor diagnóstico para este grupo, já que tais caracteres têm sido muito utilizados na Taxonomia de Leguminosae. A superfície e morfoanatomia de sementes e cotilédones foram estudadas por microscopias eletrônica de varredura e de luz, e as etapas do desenvolvimento das plântulas descritas. Embora as plântulas sejam semelhantes, caracteres de sementes (tamanho, forma, ornamentação da superfície, forma do hilo e tamanho do embrião) e cotilédones (forma, organização do parênquima lacunoso na nervura central e distribuição de metabólitos nos tecidos) apresentaram valor diagnóstico para as espécies. I. anil distingue-se de I. suffruticosa por suas sementes maiores e cotilédones com borda acuminada. I. truxillensis caracteriza-se por apresentar sementes cilíndricas e cotilédones reniformes contendo gotas de óleo e alcalóides. Nossos dados, a morfologia externa dos frutos (curvos em I. anil e I. suffruticosa, e retos em I. truxillensis) e, ainda, a anatomia foliar (células parenquimáticas grandes e fenólicas no floema de I. suffruticosa e sua ausência em I. anil) sugerem que I. anil, I. suffruticosa e I. truxillensis não devem ser sinonimizadas.

The common name "wild indigo" specifies Indigofera anil L., I. suffruticosa Mill. (legitimate name) and I. truxillensis Kunth (legitimate name) that are very similar due to their external morphology. This work analyzed diagnostic characteristics of seeds and seedlings of these species since such features are widely used in taxonomic approaches within Leguminosae. We studied surface features and morpho-anatomy of seeds and cotyledons with scanning electronic microscopy and light microscopy, and described seedling phases. Although seedlings are similar, seed characteristics (size, shape, surface ornamentation, shape of the hilum and embryo size) and cotyledon characteristics (shape, trichome ornamentation, organization of spongy parenchyma along central veins and metabolite distribution in the tissues) have diagnostic features for the species. I. anil differs from I. suffruticosa in its larger seeds and acuminate-margined cotyledons. I. truxillensis is recognized by its cylindrical seeds and kidney-shaped cotyledons with large oil drops. We assume that the characteristics examined, plus fruit morphology and foliar anatomy suggest that I. anil, I. suffruticosa and I. truxillensis should not be synonymized.

Tendo em vista a dificuldade de identificação dos ipês brasileiros em estado vegetativo, este trabalho objetivou levantar caracteres que possibilitassem reconhecê-los pela anatomia foliar (lâmina foliar e pecíolo). Folhas de seis espécies de Handroanthus (ipês amarelos: H. chrysotrichus, H. ochraceus e H. serratifolius; ipê branco: H. roseo-albus; ipês roxos: H. heptaphyllus e H. impetiginosus) e de uma espécie de Tabebuia (ipês amarelo: T. aurea) foram preparadas para observação em microscopias de luz (exame histológico) e eletrônica de varredura (exame de superfície). Caracteres provenientes da anatomia foliar possibilitaram a diagnose dos ipês, sendo mais relevantes na lâmina foliar, o número de camadas da epiderme, a posição dos estômatos em relação às demais células epidérmicas, a presença de domácias, a presença de espessamento de parede das células parenquimáticas na margem, o tipo de mesofilo e a presença de parênquima paravenal; no pecíolo, destacaram-se seu formato, a forma das células epidérmicas e a presença de fibras na região interna do floema.

By considering that Brazilian species of Ipês are hardly identified when in vegetative stage, the present study aims to research foliar anatomic characters that might allow recognize medicinal ipê species. Leaves of six species of Handroanthus (yellow flowers: H. chrysotrichus, H. ochraceus and H. serratifolius; white flowers: H. roseo-albus; purple flowers: H. heptaphyllus and H. impetiginosus) and one species of Tabebuia (yellow flowers: T. aurea) were prepared to be observed with light microscopy (free-hand cuts), and scanning electronic microscopy (surface analysis). Foliar anatomical characters allow recognizing Ipê species. The better ones provided by foliar lamina were the number of epidermic layers, the stomata position in relation to the other epidermic cells, the occurrence of domatia, the parechymatic cell wall thickening in the margin, the mesophyll type and the presence of paraveinal parenchyma; in the petiole, we can cite the petiole shape, the epidermic cell shape and the occurrence of inner phloematic fibers.

Dahlstedtia pentaphylla (Taub.) Burkart e D. pinnata (Benth.) Malme pertencem à tribo Millettieae e apresentam representantes arbóreos que produzem um odor forte e desagradável. Neste trabalho, foram investigados a distribuição, o desenvolvimento e a histoquímica de cavidades secretoras foliares e florais, que poderiam estar relacionadas a este odor. A ultra-estrutura das cavidades secretoras foliares também foi estudada e comparada aos resultados histoquímicos. Estes dados foram comparados a outros obtidos para espécies de Millettieae e discutidos sob perspectivas filogenética e taxonômica. Cavidades secretoras foliares foram observadas somente em D. pentaphylla. Cavidades secretoras florais foram observadas no cálice, nas alas e quilhas de ambas as espécies; em D. pinnata também foram encontradas nas bractéolas e no estandarte. As cavidades originaram-se por processo esquizógeno. As células do epitélio secretor apresentaram uma grande quantidade de retículo endoplasmático liso tubuloso, dictiossomos bem desenvolvidos e muitos vacúolos contendo figuras de mielina. A secreção presente no lúmen da cavidade é constituída por óleo, conforme indicam os caracteres histoquímicos e ultra-estruturais. Desta forma, o conteúdo das cavidades de Dahlstedtia não é responsável pelo odor forte e desagradável exalado pelas plantas, já que este está associado ao acúmulo de rotenona, comum em espécies pertencentes ao complexo "timbó". A ocorrência, o padrão de distribuição e a freqüência das cavidades secretoras apresentam valor taxonômico e podem ser utilizados como caracteres diagnósticos, justificando a separação das duas espécies no gênero.

Dahlstedtia pentaphylla (Taub.) Burkart and D. pinnata (Benth.) Malme belong to the Millettieae tribe and are tropical leguminous trees that produce a strong and unpleasant odour. In the present work, we investigated the distribution, development and histochemistry of foliar and floral secretory cavities that could potentially be related to this odour. The ultrastructure of foliar secretory cavities were also studied and compared with histochemical data. These data were compared with observations recorded for other species of Millettieae in order to gain a phylogenetic and taxonomic perspective. Foliar secretory cavities were only recorded for D. pentaphylla. Floral secretory cavities were present in the calyx, wings and keels in both species; in D. pinnata they also were found in bracteoles and vexillum. Such structures were found to originate through a schizogenous process. Epithelial cells revealed a large amount of flattened smooth endoplasmic reticula, well-developed dictyosomes and vacuoles containing myelin-like structures. Cavity lumen secretion stains strongly for lipids. Features of the secretory cavities studied through ultrastructural and histochemical procedures identify these structures as oil glands. Thus, if the odour produced by such plants has any connection with the accumulation of rotenone, as other species belonging to the "timbó" complex, the lipophilic contents of the secretory cavities of Dahlstedtia species take no part in such odour production. The presence, distribution patterns and frequencies of secretory structures in Dahlstedtia are taxonomically significant and may be utilized as a diagnostic character which justifies the separation of this genus into two species.

Indigofera suffruticosa e Indigofera truxillensis são espécies de Leguminosae que se destacam no gênero por suas propriedades farmacológicas. O objetivo deste trabalho foi estabelecer um controle de qualidade morfológico para as matérias-primas vegetais obtidas destas duas espécies, por meio de análises da superfície e organoléptica do pó foliolar e estudos anatômicos e histoquímicos dos folíolos, do caule e da raiz. A análise dos pós mostrou que a forma e ornamentação dos tricomas tectores são bons caracteres diagnósticos da matéria-prima pulverizada com partículas maiores que 53 µM, e que o odor em I. suffruticosa é forte e desagradável, com sabor fracamente amargo não persistente e em I. truxillensis é fraco e agradável e de sabor muito amargo e persistente. As espécies apresentaram estrutura anatômica de folíolos, entrenós caulinares e raízes laterais muito semelhantes; exceto pela epiderme papilosa em ambas as faces foliolares em I. truxillensis e apenas na face adaxial em I. suffruticosa. Compostos fenólicos foram detectados nos folíolos e alcalóides foram detectados nos caules e nas raízes (em maior quantidade nestas) de ambas as espécies. A presença de alcalóides nas raízes de I. suffruticosa e I. truxillensis é semelhante à observada em espécies de leguminosas ictiotóxicas incluídas no "complexo timbó", cujas raízes são tóxicas devido à presença de rotenóides.

The Leguminosae genus Indigofera has two important pharmacological species, Indigofera suffruticosa and I. truxillensis. The present work aims to establish a morphological quality control for vegetal drugs obtained from these two species through the analyses of surface and organoleptic features in leaflet powder, and also through anatomical and histochemical studies in leaflet, shoot and root. Powder analyses evidenced that shape and ornamentation of the simple trichomes are good diagnostic characters for the sprayed drug, with particles bigger than 53 µm; moreover, odor was strong and awkward, with non-persistent, weakly bitter taste in I. suffruticosa, and weak and pleasant, with more persistent, bitter taste in I. truxillensis. Similar anatomical structures were found in leaflets, cauline internodes and lateral roots in both species, except for papillose epidermic cells that occurred in both leaflet sides in I. truxillensis, and only on the adaxial side in I. suffruticosa. Phenolic compounds were found in leaflets, and alkaloids in shoots and roots (greater amount) of both studied species. The occurrence of alkaloids in roots of I. suffruticosa and I. truxillensis seems to be similar to that observed in ichthyotoxic legume species that belong to the so-called "timbó complex", whose roots are toxic due to rotenoids.

As sementes de Caesalpinia echinata e C. ferrea comportam-se como endospérmicas, apesar de descritas na literatura como exendospérmicas e endospérmicas, respectivamente. Desta forma, o objetivo deste trabalho foi comparar, em termos ultra-estrutural e histoquímico, a natureza das substâncias de reserva e seus tecidos acumuladores, bem como o fluxo de nutrientes nas sementes destas espécies. Os cotilédones em C. echinata acumulam carboidratos, lipídios e proteínas, mobilizados da periferia para o centro, como visto pelo posicionamento dos plasmodesmas. O endosperma em C. ferrea acumula carboidratos e lipídios, e em C. echinata, acumula substâncias nos estádios iniciais da embriogênese. Este tecido desenvolve um haustório calazal agressivo, que transporta substâncias para o endosperma propriamente dito e deste para o embrião, fato confirmado pela presença de células de transferência no endosperma.

The seeds of Caesalpinia echinata and C. ferrea behaved as typical endospermic seeds, despite their different morphological classification (exendospermic seeds were described for C. echinata and endospermic seeds for C. ferrea). Then, the aim of this work was to compare, under ultrastructural and histochemical terms, the nature of the storage substances and their accumulation sites, as well as the nutrient flow in seeds of these species. Cotyledons in C. echinata accumulate carbohydrates, lipids and proteins, which are mobilized from the outer to the inner parts as revealed by the position of plasmodesmata. Endosperm in C. ferrea accumulates carbohydrates and in C. echinata accumulates substances during the initial embryogenic phases. Such tissue develops a chalazal haustorium that is responsible for the transport of substances into the endosperm itself and from it into the embryo, confirmed by the presence of transference cells.

RESUMO O grande número de espécies e a complexidade do gênero Indigofera geram controvérsias taxonômicas de difícil resolução. Para contribuir com a taxonomia do gênero, foram levantados caracteres diagnósticos do envoltório seminal de sete espécies brasileiras de Indigofera, utilizando técnicas de exame de superfície e histológicas. As sementes são pequenas, em sua maioria rombóides mas também cúbicas ou cilíndricas, variando de verde-claras a castanho-escuras, exotestais, albuminosas, com hilo mediano, circular a ovado, de coloração conspícua. O envoltório apresentou microescultura micro a macrorreticulada, sendo constituído por macroesclereídes (com conteúdo fenólico em cinco espécies) e osteosclereídes. Embora a anatomia do envoltório da semente não tenha apresentado diferenças marcantes entre as espécies, a combinação de caracteres provenientes da microescultura da superfície seminal, da forma e do tamanho do hilo e da semente, e do número de camadas de osteosclereídes, permitiu a identificação das espécies estudadas neste trabalho. Foi concluído que a anatomia é uma ferramenta bastante útil para subsidiar a taxonomia do gênero.

ABSTRACT The large number of species and the complexity of the genus Indigofera have lead to difficult delimitation between species. In order to contribute towards the taxonomy of the genus, diagnostic characters of the seed coat of seven Brazilian species of Indigofera with the utilization of surface examination and histological techniques were explored. Seeds are small, mostly rhomboid but sometimes cuboid or cylindrical, light greenish to dark brownish, exo-testal, albuminous, with medium-sized, circular to ovate, conspicuously colored hilum. Seedcoat has micro to macroreticulate microsculpture, phenolic macrosclereids and osteosclereids. Although considerable differences among the seedcoat anatomy within species was not found, it was possible to identify the species with basis on the combination of characters from seed coat microsculpture, both shape and size of the hilum and seeds, as well as the number of layers of osteosclereids. It is concluded that anatomy is a useful tool to set taxonomical patters within Indigofera.

A distribuição dos cristais, laticíferos e grãos de amido foi estudada nos órgãos vegetativos de Dieffenbachia picta Schott (Araceae), conhecida por comigo-ninguém-pode, por tais estruturas serem citadas como responsáveis pela irritação mecânica e química provocada pela planta. A anatomia da folha, do caule aéreo, do rizoma e da raiz foi descrita por meio de seções histológicas coradas com azul de toluidina. A natureza química dos cristais e a presença de lipídios, alcalóides, grãos de amido e proteínas foram verificadas por reagentes diversos. Drusas e ráfides de oxalato de cálcio, associadas a lipídios, alcalóides e proteínas, ocorreram no interior de células presentes no parênquima de todos os órgãos, no colênquima caulinar e nos meristemas da raiz. O tempo de dissolução dos cristais das folhas jovem e adulta foi semelhante, o do caule foi maior que o da folha e o do rizoma maior que o da raiz. Grãos de amido, associados a proteínas, ocorreram no clorênquima do caule aéreo (forma de bastonetes) e rizoma (formas esférica e bastonete). Laticíferos ocorreram entremeando o colênquima e o parênquima; o látex continha ráfides, alcalóides e lipídios. Maior número de idioblastos cristalíferos e laticíferos foi observado no caule aéreo, sendo este, portanto, o órgão que mais representa perigo.

We studied the distribution of crystals, laticifers and starch grains of the vegetative organs from dumb cane, Dieffenbachia picta Schott (Araceae), known in Brazil as "comigo-ninguém-pode" for such structures are meant to be responsible for mechanical and chemical irritation events carried out by the plant. We described the anatomy of leaves, aerial stems, rhizomes and roots with histological sections dyed in toluidine blue. We checked the chemical nature of crystals and the presence of lipids, alkaloids, starch grains and proteins with various reagents. Druses and calcium oxalate raphides - associated with lipids, alkaloids and proteins - were found in idioblasts spread in the parenchyma of all organs, in the collenchyma of the shoot and in the root meristems. Regarding the dissolution time, it was analogous for crystals in both young and old leaves; it was higher in stems than in leaves and higher in rhizomes than in roots. Starch grains associated with proteins were found in the chlorenchyma of the aerial stem (rod-shaped) and in rhizomes (spherical and rod-shaped). Laticifers were found interspersing parenchyma and collenchyma; raphides, alkaloids and lipids were found in latex. We found a higher number of crystals and laticifers in the aerial stem, and therefore such structure is the most dangerous organ if eaten or swallowed.

Este trabalho estudou o efeito dos componentes de fecundidade na reprodução de Dahlstedtia pentaphylla, leguminosa neotropical com baixa produção de frutos e sementes. Para tal, foram analisadas as relações das posições das flores na inflorescência e dos óvulos/sementes no ovário/fruto ao aborto de frutos e sementes. Não ocorreram diferenças na deposição de pólen em flores e na formação de frutos em função da posição na inflorescência. Não se encontrou também relação entre aborto de óvulos/sementes e sua posição no ovário/fruto. A limitação dos recursos maternos aos frutos e aos embriões, devido ao alto custo de formação de frutos e maturação das sementes, foi um dos fatores responsáveis pelas altas taxas de aborto nesta espécie.

Studies were conducted on pollination and patterns of fruit and seed production to assess the potential factors causing high fruit and seed abortion in Dahlstedtia pentaphylla (Leguminosae) through analyses of relationships between flower position in the inflorescence and ovules and seeds within ovaries and fruits, and flower, fruit and seed abortion. No differences were found in pollination and fruit set as a function of inflorescence position. There was no relationship, neither between degenerating ovules and their position within the ovary, nor between developing seed and fruit position. Maternal resource limitation related to fruits and embryos, due to the high cost of fruit production and seed maturation, was one of the factors that led to a high abortion rate in D. pentaphylla.