17 research outputs found

    Revisão taxonômica de Myrocarpus Allemão (Leguminosae, Papilionoideae, Sophoreae) Taxonomic revision of Myrocarpus Allemão (Leguminosae, Papilionoideae, Sophoreae)

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    Em Myrocarpus, gênero exclusivamente sul-americano, são reconhecidas cinco espécies: Myrocarpus frondosus Allemão, M. leprosus Pickel, M. venezuelensis Rudd, M. fastigiatus Allemãoe M. emarginatus A.L.B. Sartori & A.M.G. Azevedo. Na delimitação das espécies são discutidos dados de morfologia, hábitats e de distribuição geográfica. A morfologia das pétalas e a ornamentação da região seminífera são caracteres relevantes na identificação das espécies, embora não utilizados até o presente. Este estudo apresenta chave de identificação das espécies, descrições, ilustrações, mapa de distribuição e novos registros de ocorrência.<br>In Myrocarpus, an exclusively South American genus, five species are recognised: Myrocarpus frondosus Allemão, M. leprosus Pickel, M. venezuelensis Rudd, M. fastigiatus Allemãoand M. emarginatus A.L.B. Sartori & A.M.G. Azevedo. Morphologic data, habitat information and geographic distribution of each taxon are discussed. Petal morphology and ornamentation of seed chamber are an important character for species identification, though not shown previously. Key to the species, descriptions, illustrations, distribution, and new registers are presented

    Towards a new classification system for legumes: Progress report from the 6th International Legume Conference

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    Legume systematists have been making great progress in understanding evolutionary relationships within the Leguminosae (Fabaceae), the third largest family of flowering plants. As the phylogenetic picture has become clearer, so too has the need for a revised classification of the family. The organization of the family into three subfamilies and 42 tribes is outdated and evolutionarily misleading. The three traditionally recognized subfamilies, Caesalpinioideae, Mimosoideae, and Papilionoideae, do not adequately represent relationships within the family. The occasion of the Sixth International Legume Conference in Johannesburg, South Africa in January 2013, with its theme "Towards a new classification system for legumes," provided the impetus to move forward with developing a new classification. A draft classification, based on current phylogenetic results and a set of principles and guidelines, was prepared in advance of the conference as the basis for discussion. The principles, guidelines, and draft classification were presented and debated at the conference. The objectives of the discussion were to develop consensus on the principles that should guide the development of the classification, to discuss the draft classification's strengths and weaknesses and make proposals for its revision, and identify and prioritize phylogenetic deficiencies that must be resolved before the classification could be published. This paper describes the collaborative process by a large group of legume systematists, publishing under the name Legume Phylogeny Working Group, to develop a new phylogenetic classification system for the Leguminosae. The goals of this paper are to inform the broader legume community, and others, of the need for a revised classification, and spell out clearly what the alternatives and challenges are for a new classification system for the family. (C) 2013 SAAB. Published by Elsevier B.V. All rights reserved

    Estudo comparativo da madeira de Mimosa ophthalmocentra Mart. ex Benth e Mimosa tenuiflora (Willd.) Poir. (Fabaceae-Mimosoideae) na caatinga nordestina

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    Pela importância econômica da madeira de algumas espécies do gênero Mimosa L. ocorrentes na caatinga nordestina e pelo fato de Mimosa ophthalmocentra Mart. ex Benth. (jurema-de-imbira), às vezes, ser confundida com Mimosa tenuiflora (Willd.) Poir. (jurema-preta) ou vice-versa, este trabalho objetivou apresentar novos dados referentes à anatomia e densidade básica da madeira das duas espécies, visando oferecer subsídio para identificação das duas espécies, identificar caracteres anatômicos da madeira relacionando-os com o ambiente caatinga e apresentar o potencial energético que sua madeira possui. O estudo anatômico e a determinação da densidade da madeira foram realizados com amostras ao nível do peito (1,30 m acima do solo) e em dois galhos com diferentes diâmetros, de espécimes ocorrentes nos municípios de Serra Talhada e Sertânia, Pernambuco, Brasil. As espécies apresentam distinção expressa através do tipo de casca, coloração do cerne e do alburno, além das características peculiares da madeira. Mimosa ophthalmocentra apresenta camadas de crescimento distintas, constituídas por linhas de parênquima axial contendo cristais, parênquima axial escasso e menor quantidade de raios por mm². Já Mimosa tenuiflora apresenta camadas de crescimento distintas, porém sem cristais, parênquima axial vasicêntrico, em faixas ou aliforme confluente, e maior percentagem de raios. Ambas apresentam algumas estruturas da madeira com as características anatômicas comuns às diversas espécies do gênero Mimosa, contribuindo assim para uma melhor caracterização do gênero. Pelos parâmetros anatômicos da madeira e pela elevada densidade básica (>0,84 g/cm³), concluiu-se que as duas espécies apresentam perspectivas seguras para a produção de álcool combustível e carvão vegetal desde a fase de lenho juvenil. Mimosa ophthalmocentra apresenta maior potencial energético, pela maior percentagem de fibras e por possuir parênquima escasso e menor percentagem de raios.<br>Due to the economic importance of the wood of Mimosa L. species in Northeastern Brazil's caatinga and to the fact that Mimosa ophtalmocentra Mart. ex Benth. ("jurema-de-imbira") is confused with Mimosa tenuiflora (Willd.) Poir. ("jurema-preta") and vice versa, this research aimed to present new data related to the anatomy and basic density of the wood of both species; to contribute to the taxonomic study for differentiating them; to identify anatomical characters of the wood relating them to the caatinga environment; and to present the energetic potential that they possess. The anatomical study and wood density determination were carried out with samples at dbh level and with two branches of individuals within the municipalities of Serra Talhada and Sertânia (Pernambuco). The species both differed in bark type, color of heartwood and sapwood, besides the different anatomical characteristics found in the wood. Mimosa ophtalmocentra has distinct growth layers consisting of parenchyma lines containing crystals, scarce parenchyma and smaller quantity of rays. Mimosa tenuiflora, on the other hand, also has growth layers, but without crystals, axial parenchyma vasicentric, confluent and in bands, and greater percentage of rays. Both species have some wood elements with anatomical characteristics typical of representatives of Mimosa, contributing therefore to a better taxonomic understanding of the genus. Based on wood anatomical parameters and elevated basic density (> 0.84 g/cm³), the conclusion was reached that both species have great perspectives for the production of fuel alcohol and charcoal since juvenile wood age. Because Mimosa ophthalmocentra has scarce parenchyma and fewer rays, it shows greater energetic potential than Mimosa tenuiflora
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