Anatomia da madeira de 50 espécies de gimnospermas: enfoque taxonômico

Abstract

The group of gymnosperms is formed by four subclases: Cycadidae, Ginkgoidae, Gnetidae and Pinoidae, comprises about 15 families, 5-80 genera and 800 species, which grow in most of the planet, from 72° north to 55° south and are the dominant vegetation in the cold and arctic regions. The group is known under the technological point of view as a producer of softwood. The overall species are gregarious enabling greater volumes of wood and good silvicultural qualities and can be used for afforestation. The aim of this study is to characterize anatomically wood 50 species of gymnosperms among families Cycadaceae, Ginkgoaceae, Ephedraceae, Gnetaceae, Welwistchiaceae, Araucariaceae, Podocarpaceae, Cupressaceae, Sciadopityaceae, Taxodiaceae and Pinaceae. The histological slides and macerate were made from donated wood samples by Jodrell Laboratory (Kew Gardens, Londres), by New York Botanical Garden, and by University of Utrecht e Hamburgo, according to standard techniques used in wood anatomy. The wood descriptions were based on IAWA Committee (2004). The subclasses Cycadidae, Gnetidae and Pinoidae, can be anatomically identified, as well as some of the botanical families. For the separation of species and genera, it was often necessary to use quantitative data. The anatomy of wood has proved to be very useful to support the taxonomy studies of Gymnosperms.