Morfoanatomia foliar de Chrysobalanaceae R. Br. da Reserva Florestal Adolpho Ducke

Abstract

The internal taxonomical organization of the Chrysobalanaceae is problematical and studies are needed with large numbers of taxa. This work is an anatomical and morphological description of 20 species of Chrysobalanaceae from the genera Couepia, Licania and Parinari occurring in the Adolpho Ducke Forest Reserve, Manaus AM. Morphological observations were made using a stereomicroscope. In addition, leaves were cleared with sodium hydroxide to see details of venation pattern. We characterized the epidermis frontal view using the method of dissociation with Franklin solution and paradermal cuts. The petiole, midrib and mesophyll were analyzed by cross sections from the middle third. The species analyzed herein have the basic morphological pattern described for the family, with simple, alternate, distichous, petiolate leaves with stipules usually present in younger branches. Macroscopic characters such as the shape of the blade, stipule type and the presence or position of glands vary between species. The most recurrent venation pattern among the species studied is the eucamptodromous with the occurrence in some cases of mixed eucamptodromous / broquidodromous venation. The petiole vascularization in all species is formed by continuous or discontinuous rings, or two or three arcs. The vascular bundles of the midrib are organized into arcs formed by two or three collateral bundles or forming a closed ring which may present an inner phloematic arc. The predominant type of anticlinal contour in the upper surface of the leaves is straight, with varying forms in the lower surface. The species have paracytic stomata, some occurring in stomatal crypts. The mesophyll of all species is dorsiventral, with both sides lined by a thick cuticle in several species. The epidermal cells on the adaxial surface are tabular, cubic or rectangular in shape. Palisade tissue occurs in one to three layers of elongated cells and spongy parenchyma compression varies according to the species. Sheath extensions and columnar sclereids occur in various species. An identification key was developed, as well as standardized descriptions using morphological and anatomical features. The following anatomical characters contributed more to the diagnosis, showing greater variation per feature, and were of most use in the key: position of glands, position of stomata in the epidermal line, shape of the stipules, number of layers of the upper epidermis, number of accessory vascular bundles in the petiole and development of areoles. The character set is effective in differentiating between species.