Anatomia do lenho do gênero Dimorphandra schott (Caesalpiniaceae)

Abstract

The present work approaches the anatomical study and some aspects of phylogenetic importance of the secondary xylem of 23 species of Dimorphandra. The following species were studied: Dimorphandra campinarum Ducke, D. caudata Ducke, D. coccinea Ducke, D. conjugata Sandwith, D. cuprea Sprague & Sandwith subsp. cuprea, D. cuprea Sprague & Sandwith subsp. ferruginea (Ducke) M. F. Silva, D. davisii Sprague & Sandwith, D. exaltata Schott, D. gardneriana Tulasne, D. gigantea Ducke, D. ignea Ducke, D. macrostachya Bentham subsp. macrostachya, D. macrostachya Bentham subsp. congestiflora (Sprague & Sandwith) M. F. Silva, D. macrostachya Bentham subsp. glabrifolia (Ducke) M. F. Silva, D. mollis Bentham, D. multiflora Ducke, D. parviflora Spruce ex Bentham, D. pennigera Tulasne, D. polyandra Benoist, D. pullei Amshoff, D. unijuga Tulasne, D. vernicosa Spruce ex Bentham & Hook. f .e D. wilsonii Rizzini. The anatomical characteristics macro and microscopic of the wood were described individually and the anatomical aspects were analysed so much qualitative as quantitative of the constituent elements of the secondary xylem. It was observed, for most anatomical characteristics, a great structural homogeneity among the species. For each species are presented: common names, general characteristics of the wood, distribution, macro and microscopic descriptions, macrophotograph of the transverse section, microphotographs of the transverse, tangential and radial planes, biometric records of the anatomical elements and a table of occurrence of crystals and silica in the tissues. Based on certain characters of the xylem, prevailing the quantitative characters, just with value diagnosis, it was elaborated a key that allowed to divide the species through the subgenera, for separation and identification of the same ones. The anatomical characteristics of the timber such as: vascular length, frequency of the vessels by mm², tangential diameter, presence or absence of vessel appendix, fiber length, ray width and the nurnber of cells, presence or absence of crystals and silica allow to separate the species in groups. On the other hand the configuration of the axial parenchyma and opposite intervascular pits allows to separate the species isolately.