Recebido em 3/01/2008. Aceito em 25/06/2008 RESUMO -(Anatomia foliar de espécies de Myrtaceae: contribuições à taxonomia e filogenia). Trabalhos taxonômicos e filogenéticos têm utilizado informações anatômicas e para contribuir com estes estudos examinaram-se cortes paradérmicos e transversais da porção mediana foliar de Campomanesia adamantium (Camb.) O. Berg, Myrcia cordiifolia DC., M. decrescens O. Berg e M. torta D.C. Os caracteres anatômicos foram comparados com os de outras espécies descritas na literatura. São características comuns às quatro espécies examinadas: epiderme uniestratificada, tricomas unicelulares, folhas hipoestomáticas, estômatos paracíticos, cavidades secretoras em ambas as faces, mesofilo dorsiventral e nervura mediana com feixes bicolaterais. Destacam-se os seguintes caracteres úteis para a taxonomia da família: formato das células comuns da epiderme, tricomas dibraquiados ou não, camadas celulares incolores subepidérmicas e formato da nervura mediana. O formato e número das células teto das glândulas foliares têm utilidade taxonômica. O exame de 144 exsicatas evidenciou que a glabrescência é um fenômeno comum. A queda dos tricomas pode ser devido à sua base estreita e à ausência de célula pedal nos mesmos. Analisaram-se os caracteres à luz de estudos filogenéticos recentes e do ponto de vista ecológico, destacando a hipótese relacionada às células epidérmicas com possível função de célula de transferência. As características anatômicas forneceram dados para análises comparativas mais amplas entre os táxons de Myrtaceae e possibilitaram a construção de um cladograma, onde espécies de Leptospermum e Eucalyptus ocuparam posição basal, em consonância com filogenias relatadas na literatura. Palavras-chave: célula de transferência, célula teto, evolução, folha, taxonomiaABSTRACT -(Leaf anatomy of Myrtaceae species: contributions to the taxonomy and phylogeny). Taxonomical and phylogenetical studies have used anatomical information. In order to contribute to these studies, paradermal and cross sections of the median leaf blade portion of Campomanesia adamantium (Camb.) O. Berg, Myrcia cordiifolia DC., M. decrescens O. Berg and M. torta D.C. were examined. The anatomical characters were compared to the other species described in the literature. Some characteristics were irrespective of the four examined species: unistratified epidermis, unicellular trichomes, hypostomatic leaves, paracytic stomata, oil glands on both sides, dorsiventral mesophyll and bicollateral bundles on the midrib. The following characters appear to be taxonomically useful in the family: epidermal common cell format, presence of dibrachiate trichomes, presence of colorless subepidermal cell layers and midrib shape. The morphology and number of overlying cells associated with the glands have taxonomic utility. The 144 exsicates examination showed that the glabrescence is a widespread phenomenon in the Myrtaceae. The trichome fall can be due to its narrow base and to the foot cell absence. The characters were analyzed in the...
RESUMENFueron estudiadas las hojas de 18 especies de Lauraceae que crecen en el Distrito Federal (Brasil), con el objetivo de caracterizar sus patrones de venación e identifi car características útiles en su diferenciación taxonómica, para que junto a su morfología se puedan obtener criterios útiles que ayuden en su identifi cación vegetativa. Las hojas fueron diafanizadas, coloreadas y fotografi adas. Los patrones de venación del segundo, tercero, cuarto y quinto orden fueron descritos e ilustrados para las especies estudiadas, que presentaron una venación secundaria de tipo broquidódroma o eucamptódromo-broquidódroma, excepto en Crytocarya aschersoniana y Ocotea aciphylla con venación broquidódroma promínula reticulada. La densidad de areolas se mostró como un buen carácter taxonómico, lo que no ocurrió con el número de lados que éstas poseen. Fueron propuestos los conceptos de nudos y ramas de las vénulas y criterios para la clasifi cación de sus ramifi caciones. La mayoría de las especies poseen vénulas ramifi cadas. Los caracteres analizados, unidos con los morfológicos tales como tipo de indumento, formas de borde, y presencia y/o ausencia de domacios, posibilitaron la diferenciación de las 18 especies estudiadas, evidenciando la clara importancia de la arquitectura foliar en el reconocimiento taxonómico de especímenes en estado vegetativo. PALABRAS CLAVE:Arquitectura foliar, morfología de las hojas, venación foliar. ABSTRACTLeaves of 18 species of Lauraceae that grow in the Distrito Federal (Brazil) were studied with the goal of characterizing their venation patterns and to identify useful traits in taxonomic differentiation, so that along with their morphology can be achieved concise criteria that help in vegetative identifi cation. The leaves were cleared, stained and photographed. Venation patterns of second, third, fourth and fi fth order were described and illustrated for the studied species, which showed brochidodromous or eucamptodromous-brochidodromous secondary venation pattern, except Cryptocarya aschersoniana and Ocotea aciphylla that presented brochidodromous prominulous-reticulate venation. Areole density was found to be a good taxonomic character, which did not happen with the number of sides that they have. The concepts of the venule nodes and branches and the criteria for the classifi cation of its branches were proposed. Most species have branched venules. The analyzed characters together with the morphological ones, such as margin shape and presence or absence of domatia, allowed the differentiation of the studied species, demonstrating the clear importance of leaf architecture in the taxonomic recognition of specimens in a vegetative state.
The genus Peristethium, characterized by determinate inflorescences protected by deciduous bracts, occurs in the northwest of South America, as well as Costa Rica and Panama. The main objective of this paper was to transfer one species to what we believe is its correct generic placement in Peristethium, that likewise implies in a shift of the genus' distribution beyond the Amazon. A new combination, Peristethium reticulatum, is proposed, based on Struthanthus reticulatus, described from Tocantins in 1980. The sexual dimorphism of the inflorescences of P. reticulatum (sessile male flowers and pedicellate female flowers) associated with male inflorescences that are inserted at leafless nodes are unique within the genus. The male flowers have dimorphic stamens, well-developed anthers and a pistiloid, whilst female flowers have robust styles and stigmas, and much reduced staminodes. Peristethium reticulatum and P. polystachyum occurs in the Amazon regions of Brazil, with the former recorded also in the ecotone with the Central Brazilian savannas (Cerrados).
RESUMO(Novos sinônimos e uma nova combinação em Pusillanthus (Loranthaceae)). Uma revisão de Pusillanthus Kuijt para o Brasil é apresentada. O gênero monotípico recém-descrito ocorre na Venezuela, Guiana e Brasil. No Brasil, distribui-se somente na Caatinga, nos estados de Alagoas, Bahia e Paraíba. A nova combinação Pusillanthus pubescens (Rizzini) Caires é proposta e as espécies Phthirusa caatingae Rizzini, Pusillanthus trichodes (Rizzini) Kuijt e Struthanthus pubescens var. bahiensis Rizzini são tratadas como seus sinônimos taxonômicos. Uma prancha ilustrativa e um mapa de distribuição para o gênero no Brasil são apresentados, bem como estudos da arquitetura foliar, de superfícies de caule, folha e grãos de pólen usando Microscopia Eletrônica de Varredura.Palavras-chave: arquitetura foliar, Brasil, Caatinga, ginomonoicia, Nordeste, Pusillanthus pubescens ABSTRACT (New synonyms and a new combination in Pusillanthus (Loranthaceae)). A revision of Pusillanthus Kuijt for Brazil is presented. The recently described monotypic genus occurs in Venezuela, Guyana, and Brazil. In Brazil, it is distributed only within the Caatinga domain, in the states of Alagoas, Bahia and Paraíba. The new combination Pusillanthus pubescens (Rizzini) Caires is proposed and the species Phthirusa caatingae Rizzini, Pusillanthus trichodes (Rizzini) Kuijt, and Struthanthus pubescens var. bahiensis Rizzini are treated as its taxonomic synonyms. An illustrative plate and a distribution map for the genus in Brazil are presented, as well as information about leaf architecture, and stem, leaf, and pollen grain surfaces (based on scanning electron microscopy).
The difficulty of identifying Lauraceae species is well known. The leaf epidermis of 18 species from the Federal District, Brazil, was analyzed to test more characters as an aid to the taxonomy of this family. New anatomical characters are proposed here, such as sinus number, internal angles and number of sides of the common epidermal cells, their arrangement around the trichome base, and the shape and width of the subsidiary cells in relation to the guard cells. Epidermal characters that can aid in the identification of the studied species are: the contour of the common cells on both leaf surfaces and their anticlinal wall width, number of sides of the polygonal cells, sinus number, presence of angles greater than 180°, presence and type of indumentum, common cells with radial arrangement around the trichome base, stomatal position relative to the rest of the epidermis and width of the subsidiary cells in relation to the guard cells. Glabrous and glabrescent leaves are distinguished. Two species have unique characters: Aniba heringeri, with papillae on the abaxial surface, and Cryptocarya moschata, with peculiar horseshoe-shaped subsidiary cells. Characters of the epidermis together with the external leaf morphology are sufficient to distinguish the studied species. Additionally, we report for the first time the occurrence of Mezilaurus crassiramea and Ocotea diospyrifolia for the flora of Federal District, Brazil.
A new species, Myrcia proencana is described from eastern Bolivia. It is known from the Serranía de Huanchaca in the Noel Kempff Mercado National Park. M. proencana is compared with M. torta which is the species most similar. Also, we determined that Psidium hians should be considered as an accepted name, and P. nutans should be included in its synonymy. Additionally, Eugenia paranahybensis, E. pitanga, E. suberosa, Psidium misionum and P. myrsinites are reported as new records for the Bolivian flora.
During our studies of the Brazilian Loranthaceae, an extensive review of names associated to Oryctina and Passovia was carried out. We observed that the leaf architecture and floral structure of Oryctina myrsinites were different from that of other species of the genus. Analyses under Light and Scanning Electron Microscopy showed stellate fiber bundles in the mesophyll, inflorescences formed by sessile triads and laterally excavated filaments. Epicortical roots at the base of the plant were also observed. These characters are diagnostic of Passovia, and we agree with Van Tieghem that Passovia myrsinites is the correct name for this species and have also included Oryctina atrolineata as a new synonym.
Myrcia macrocalyx, a new species from Cavalcante, Goiás, Brazil, is here described and illustrated. Additional details on the leaf architecture, geographical distribution, and conservation status of this species are also provided.
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