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Item Morphoanatomy of nectaries of Chamaecrista (L.) Moench sections Chamaecrista, Caliciopsis and Xerocalyx (Leguminosae: Caesalpinioideae)(Acta Botanica Brasilica, 2017-07) Silva, Marinalva dos Santos; Coutinho, Ítalo Antônio Cotta; Araújo, Maicon Nascimento; Meira, Renata Maria Strozi AlvesNectaries are specialized structures that secrete nectar. Several species of Chamaecrista possess nectaries on the petiole, which have been shown to vary widely in morphology and the chemical nature of their secretion. However, a comprehensive investigation of the nectaries of the clade formed by sect. Chamaecrista, Caliciopsis and Xerocalyx has yet to be performed. Our study aimed to confirm whether or not the leaf glands of species of this clade are in fact nectaries, determine the chemical nature of their secretion and expand the morphoanatomical database on leaf nectaries in Chamaecrista with the intention of contributing to the taxonomy and phylogeny of the genus. Samples from herbarium and field-collected material were subjected to standard methods for light and scanning electron microscopy. Four different forms of nectaries were observed: urceolate, patelliform, verruciform and cupuliform. The nectaries were found to comprise a single-layered epidermis, nectary parenchyma, subnectary parenchyma and vascularization. Polysaccharides, lipids, phenolic compounds and proteins were detected in secretions. Although anatomical similarities were observed among the studied species, their morphology differed. Moreover, the glands are indeed nectaries and are similar to those observed in other species of the genus Chamaecrista. These data hold potential taxonomic usefulness for the studied sections.Item Colleters in Chamaecrista (L.) Moench sect. Chamaecrista and sect. Caliciopsis (Leguminosae-Caesalpinioideae): anatomy and taxonomic implications(Acta Botanica Brasilica, 2017-07) Silva, Marinalva dos Santos; Coutinho, Ítalo Antônio Cotta; Araújo, Maicon Nascimento; Meira, Renata Maria Strozi AlvesThe genus Chamaecrista contains ca. 330 species organized into six sections, of which section Chamaecrista is the second largest (ca.75 species) distributed among six series, while the section Caliciopsis contains only two species. Colleters have been described in the genus Chamaecrista and they show potential taxonomic and phylogenetic significance. They are associated with lubrication, desiccation prevention and protection from microbial attacks of young developing organs. Although six types of colleters have been described for the genus Chamaecrista, there have been no studies focusing on the diversity of colleters in the sections Chamaecrista and Caliciopsis. Samples from developing leaves and flowers of both sections were obtained from herbarium and field collections and subjected to standard methodologies for both light and scanning electron microscopy. Histochemical tests were also performed to determine the nature of the exudates. Five types of non-vascularized colleters were found: short digitiform, long digitiform, club-shaped, pyriform and short bottle-shaped. Polysaccharides, pectins, lipids and proteins were detected in the exudates of all types of colleters. Among the five types of colleters observed, pyriform is a novelty for Chamaecrista, reinforcing the significant morphological diversity of these secretory structures in this genus.Item A study of the morphoanatomical characters of the leaves of Chamaecrista (L.) Moench sect. Apoucouita (Leguminosae-Caesalpinioideae)(Acta Botanica Brasilica, 2013-04) Coutinho, Ítalo Antônio Cotta; Rando, Juliana Gastaldello; Conceição, Adilva de Souza; Meira, Renata Maria Strozi AlvesLittle attention has been paid to species of Chamaecrista sect. Apoucouita (Leguminosae-Caesalpinioideae), especially regarding anatomical studies. When only vegetative material is available, the identification of such species may be difficult. Additionally, vegetative material of some species of C. sect. Apoucouita may be even harder to identify because they can resemble species of Inga Mill. (Leguminosae-Mimosoideae). The present study focused on recognizing morphoanatomical characters of leaves that are taxonomically useful for the species of C. sect. Apoucouita by employing standard anatomical techniques. The arrangement of the vascular system in the petiole/rachis, dorsiventral mesophyll, mucilage idioblasts in the epidermis of leaflets and hypostomatic leaves were some of the characters shared by all species studied. Length of the petiole, position and type of extrafloral nectaries, leaflet venation, presence and type of papillae on the epidermis of the leaflet blades and sclereids in the mesophyll were some of the characters useful in the distinction of taxa. The vascular arrangement of the petiole/rachis is a promising character in the distinction of species of C. sect. Apoucouita and Inga. Based on morphoanatomical data, the taxonomic revision of some species and varieties ascribed to C. sect. Apoucouita is suggested.Item Colleters in 10 species belonging to three tribes of Rubiaceae: morphoanatomical diversity and potential as useful characters for taxonomy(Botany, 2015-07) Otuki, Sara Akemi Ponce; Azevedo, Aristéa Alves; Pereira, Zefa Valdivina; Meira, Renata Maria Strozi Alves; Lopes-Mattos, Karina Lucas BarbosaColleters are common secretory structures in Rubiaceae. In this study, we describe colleter morphoanatomy and histochemistry in 10 species belonging to Chiococceae, Coussareae, and Psychotrieae tribes of Rubiaceae. Colleter morphoanatomy was analyzed by light and scanning electron microscopy. Microscopy analysis revealed that colleters were present on the stipule adaxial surface in all species. In the case of Palicourea marcgravii A.St.-Hil. and Chiococca alba Hitchc., colleters were also found on leaf primordia and at the stipule apex, respectively. Colleters were classified into three types: standard, bifurcated standard, and reduced standard. Further analysis showed that colleter epidermal cells are thin-walled and possess a thin cuticle, conspicuous nuclei located at the equatorial or basal region, and abundant cytoplasm. Intercellular spaces were found among epidermal cells in Chiococca alba, Coussarea triflora Müll.Arg., Coussarea verticillata Müll.Arg., Psychotria conjungens Müll.Arg., and Psychotria sessilis Vell. Crystalliferous idioblasts containing raphides were observed in the colleter central parenchymatous axis of all species, while crystal sand was found only in Chiococca alba. Histochemical tests revealed that colleter secretion is composed of a mixture of mucilage and protein. We conclude that colleter position, typological variation, presence of vascularization, and type of calcium oxalate crystals represent promising characters for future taxonomic and phylogenetic studies in Rubiaceae.Item Anatomical characteristics as taxonomic tools for the species of Curtia and Hockinia (Saccifolieae–Gentianaceae Juss.)(Plant Systematics and Evolution, 2013-06-25) Dalvi, Valdnéa Casagrande; Meira, Renata Maria Strozi Alves; Francino, Dayana Maria Teodoro; Silva, Luzimar Campos; Azevedo, Aristéa AlvesThe delimitation of species and even support of the genera Curtia and Hockinia, monotypic genus, are still controversial. To define anatomical characteristics that help resolve taxonomic problems, the stem and leaf anatomy of seven species of Curtia and Hockinia montana are described. Some characteristics are found in both genera: leaves with uniseriate epidermis, dorsiventral mesophyll, cells of the palisade parenchyma with invaginations, basal acrodromous venation with an incomplete marginal ultimate venation, presence of colleters and nectaries, stem with small wings and internal phloem. The types of stomata, the midrib vascular bundle, and the type and distribution of nectaries were used to separate the genera. The presence/absence of crystals, the sinuosity of the anticlinal walls of the epidermal cells, the type and distribution of stomata, and the distribution of nectaries distinguish species of Curtia. Our results suggest that these anatomical characteristics are potentially useful for clarifying the taxonomy of Gentianaceae, and that they represent an additional tool for distinguishing genera and identifying species of Curtia, particularly pointing out the need to revise the synonymy between C. patula and C. tenuifolia. We also highlight the first report of leaf nectaries and colleters in the Saccifolieae and the first record of stem nectaries in the Gentianaceae.Item Leaf anatomy as an additional taxonomy tool for 16 species of Malpighiaceae found in the Cerrado area (Brazil)(Plant Systematics and Evolution, 2010-04-14) Araújo, Josiane Silva; Azevedo, Aristéa Alves; Silva, Luzimar Campos; Meira, Renata Maria Strozi AlvesThis 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.