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The development of the pollen grains is a complex and regulated process. However, failures in sporogenesis and gametogenesis are common and include cell division errors and multiple structural modifications, culminating usually in abortions or, less frequently, in formation of anomalous pollen grains. These anomalies include altered morphology and functionality and are reported in several species, but are still unexplored in Bromeliaceae, a diverse neotropical family. Thus, this work structurally describes anomalous pollen grains in anthers of Dyckia racinae L.B. Sm., a Bromeliaceae species endemic to Southern Brazil. Mature anthers were processed and analyzed using standard methods for light microscopy. In addition to structurally normal pollen grains, unicellular, geminate, voluminous and aborted pollen grains were structurally described. These morphological alterations include differences in developmental destination, pollen grains with varied sizes, fusions with cytoplasmic communications, morphological alterations in exine and intine and variations in the cytoplasmic content. These anomalies are normally related to developmental disruptions, such as altered programmed cell death in tapetum, associated with cytoplasmic male sterility, for example, which usually leading to extensive abortion of the pollen grains in the anther locules. The structural anomalies described in this study, however, occur in anthers with apparently normal development and were first described for Bromeliaceae. Our results suggest a partial male sterility for this species, an unexplored embryological aspect of pollen grains in this family. Future investigations of ultrastructure and development of the anomalous pollen grains should contribute to a better understanding of the reported anomalies.

Hesperozygis ringens (Benth.) Epling is an endangered Lamiaceae woody herb characterized by the abundance of essential oil (EO) in its leaves. However, no information has been found in literature about the plant tissues where this extractive is biosynthesized, and what other constituents are produced by the organ. In addition, the classes of compounds biosynthesized by its petals and the composition of EO produced by the inflorescences have not been reported either. Because this information may help the H. ringens identification, the aim of this study was to characterize the compound classes in the plant leaf and petal by histochemical tests. The leaves and flowers of this species were collected from a population in Santo Antao, municipality of Santa Maria, Rio Grande do Sul, Brazil. Fresh plant material was analyzed to detect total lipids; acid and neutral lipids; essential oils (EOs), resins and oil-resins; proteins; starch; phenolic compounds; tannins; flavonoids; and alkaloids. The EOs of leaves and inflorescences were extracted by hydrodistillation and their chemical compositions were analyzed by gas chromatography coupled to mass spectrometry (GC–MS) and GC with flame ionization detector. Results obtained in histochemical tests detected total, neutral and acid lipids, EOs, oil-resins, protein, phenolic compounds, flavonoids and alkaloids in the leaves and petals of H. ringens. Total lipids were found mainly in leaf mesophyll and glandular trichomes of both plant organs. Essential oils were marked in leaf vascular bundle, petal surface and glandular trichomes of both fresh organs. Oil-resins were detected mainly in leaf mesophylls and petal glandular trichomes. The chemical characterization of the EOs produced by leaves and inflorescences detected the oxygenated monoterpenoid pulegone as their major compound. The species presented histochemical characteristics which have not been found for other Lamiaceae representatives yet, and may serve to identify H. ringens.

The aim of this study was to describe the structural characterization of Hesperozygis ringens (Benth.) Epling vegetative organs. For this purpose, leaves, stems and roots of the endangered Lamiaceae were collected from a population located in Santo Antão, Santa Maria municipality, Rio Grande do Sul, Brazil. Results demonstrated that the H. ringens leaf blade presents glandular and non-glandular trichomes as well as two morphs of diallelocytic stomata, which are usually found above the epidermis level. The petiole is concave on ventral face and convex on its dorsal face, containing glandular and non-glandular trichomes as well as stomata in the epidermis. These types of trichomes were also detected in the stem. In addition, the presence of intercellular spaces within the organ is highlighted. Stomata above epidermis level also occurred in the stem. Phenolic idioblasts were found in the cortical region of plant root and deposit of lipophilic substance was observed in phloem cells. Great amount of apparently two different crystals were detected in all organs. Information obtained in this study provides knowledge about the characterizationof H. ringens, which may be used to distinguish characters of taxa and can help understand the species survival in its occurrence sites.

This paper presents a morphological analysis of the flower and floral trichomes of three rare species of Dyckia: Dyckia ibicuiensis, D. polyclada and D. racinae. Flowers at anthesis were collected from natural populations and subjected to morphometric and microscopic analysis. Among the most representative features for Dyckia are: morphometrics of individual floral parts; the general configuration of the androecium and gynoecium; the degree of fusion of the stigmatic lobes; the morphology of the ovules, especially in relation to the chalazal appendix; and the presence and constitution of peltate trichomes in the perianth, which exhibited a polymorphism not previously reported for Dyckia. The characters were effective at describing each species, proposing phylogenetic inferences and recognizing infrageneric groupings. We propose two species groups, which are consistent with previous hypotheses about the relationships among the species of the genus. The objective of this study was to provide floral morphological data useful for characterizing these three rare species, delimiting the genus and forming phylogenetic hypotheses.

This study presents a morphoanatomical analysis of Dyckia ibicuiensis , D. polyclada and D. racinae stamens. Flowers at anthesis were desiccated and their stamens were processed using common light microscopic techniques. Morphologically, the androecium in these species is differentiated by the disposition of the stamens around the gynoecium and by general anther characteristics. Included stamens, with antesepalous filaments different from those of the antepetalous, anthers in a radial disposition, always curved, and sporangia facing the gynoecium characterize D. ibicuiensis and D. racinae . This configuration results from the filament connation, as well as special anatomical characteristics of the anthers, such as the connective with thickenings. In addition, these species are differentiated by the U-shaped thickening in the endothecium. D. polyclada is characterized by its small, free and exserted stamens, with a very short common tube, its anthers, that are not curved or organized around the gynoecium, and its divergent sporangia. The anatomical and morphological characteristics identified here are important for characterization of these species. Considering that the androecium is important in the delimitation of Dyckia , the increased use of these data should be equally important for other species and infrageneric groupings.

Amphilophium crucigerum (L.) L.G. Lohmann, known as “pente-de-macaco” is a species of Bignoniaceae native to Brazil, and whose seeds are used in folk medicine. This study aimed to describe morphoanatomical features of this species of fruit to aid in its correct identification and pharmacognostic analysis. Samples of ovary, pericarp and seed were fixed with 3% glutaraldehyde, sectioned on a rotary microtome and analyzed by stereomicroscope. The results are shown in three parts: (1) The ovary presents peltate trichomes, long non-glandular trichomes and emergences in the epidermis; it is 2-carpellate and unilocular with two intruding parietal placenta; ovules are numerous on the placenta; it presents a large quantity of crystals. (2) The pericarp is woody, densely echinate and elliptic shape; it presents a 2-valved capsule and is septicidal; it presents emergences, stomata, lenticels, crystals and a large quantity of clustered stones cells. (3) Seeds are alate, exalbuminate and exotestal; there is a large amount of crystals in the exotestal region; it presents an endothelium and remnant endosperm. Histochemical tests showed the presence of lipophilic substances, polysaccharides, phenolic substances, alkaloids and a small quantity of starch. These pharmacobotanical features described for A. crucigerum are essential for the pharmacognostic analysis of the drug plant. Keywords: Crystals, Histochemical, Morphoanatomy, Ovary, Seed, Trichomes

Investigation into the initial developmental stages of a given structure is fundamental for precise characterization as well as for comparative analysis in relation to other taxa when homologies are established. For the Anacardiaceae family, investigations of the initial development of the pericarp or its basic histological sites, the epicarp, mesocarp and endocarp, are relevant since these regions are of taxonomic and phylogenetic importance. The initial stages of endocarp development in Lithraea brasiliensis were studied using light microscopy. In L. brasiliensis, the fruits are of the drupe type. The endocarp originates exclusively in the epidermis of the locular cavity and is composed of only three strata. The crystalliferous layer, typical in fruits of the Anacardiaceae family, originates in the carpelar mesophyll and runs adjacent to the outermost layer of the endocarp. The endocarp in Lithraea brasiliensis is of the Anacardium type. The results of the present study are important for the identification of theLithraea species that occur in the state of Rio Grande do Sul. In L. molleoides, the crystalliferous layer was shown to originate from the locular epidermis and this developmental aspect enables it to be differentiated from L. brasiliensis and demonstrates that there is variability of endocarp development in Lithraea. O estudo do desenvolvimento inicial de uma determinada estrutura é fundamental para sua precisa caracterização e análise comparada a outros táxons, quando são estabelecidas homologias. Para a família Anacardiaceae, estudos sobre o desenvolvimento inicial do pericarpo ou de seus sítios histológicos básicos, epicarpo, mesocarpo e endocarpo, se mostram relevantes, pois tais regiões possuem importância taxonômica e filogenética. O desenvolvimento inicial do endocarpo em Lithraea brasiliensis, foi estudado por meio de microscopia de luz. Em L. brasiliensis, os frutos são do tipo drupa. O endocarpo se origina exclusivamente da epiderme da cavidade locular e é composta por apenas três estratos. A camada cristalífera, típica nos frutos da família Anacardiaceae, possui origem no mesofilo carpelar e ocorre adjacente a camada mais externa do endocarpo. O endocarpo em Lithraea brasiliensis é do tipo Anacardium. Os resultados do presente estudo são importantes para a identificação das espécies de Lithraeaque ocorrem no estado do Rio Grande do Sul. Em L. molleoidesfoi demonstrado que a camada cristalífera surge da epiderme locular e este aspecto do desenvolvimento permite diferenciá-la de L. brasiliensis e que existe, portanto, variabilidade associada ao desenvolvimento do endocarpo em Lithraea.

Although this study aims to develop an improved method for the preservation of reserve lipids in plant tissues for different uses in plant anatomy, it mostly aims to develop an improved method for the identification of lipid reserves where synthesis or storage occurs. The proposed procedures entail only the utilization of (2-hydroxyethyl)-methacrylate (HEMA) as a dehydration agent. One of the procedures is based on the gradual exchange of aqueous HEMA solutions with increasing concentrations. In another procedure, dehydration and infiltration are induced by the presence of silica gel around a modified microcentrifuge tube containing the aqueous HEMA solution with the plant tissues, thus allowing efficient lipid preservation. Both procedures resulted in simultaneous dehydration and infiltration of the endosperm and embryo of Ricinus communis, while eliminating the use of ethyl alcohol, thus providing better lipid preservation.

This paper presents a comparative description of the starch distribution in the anthers, microspores and pollen grains of Aechmea recurvata, Dyckia racinae and Tillandsia aeranthos. Flowers at different stages of development were processed according to plant microtechniques for observation by light microscope. Ten stages of embryological development were used as references for the comparative analysis of starch distribution and dynamics. The structural data showed a greater starch accumulation in the parietal layers and connective of D. racinae. It was observed that in the species studied, starch began to accumulate in microspore mother cell stage. The pollen grains in D. racinae and in T. aeranthos present two amylogenesis-amylolysis cycles, while A. recurvata presents only one. One amylogenesis-amylolysis cycle occurs in the parietal layers and/or connective tissue in all three species. The pollen grains in the three species are dispersed without starch and are characterized as the starchless type. Starch dynamics presents a close relation to the development of sporangia, microspores and pollen grains. It is believed that differences in the starch distribution and accumulation are related to the abiotic factors where the species are found.