Morfoanatomia de desmoncus polyacanthos c. martius de terra firme

Abstract

O. polyacanthos C. Martius (Arecaceae) is popularly known as "jacitara". It presents several ethnobotanical indications with the use of its fibers in baskets and ropes. The objective of this work was to characterize the anatomy of the vegetative organs of the species in a dryland environment. Collected at the Research Campus of the Museu Paraense Emílio Goeldi, the material was submitted to the usual techniques in plant anatomy and histochemistry and photomicrographed. For the SEM analysis, the images were obtained at the Institutional Laboratory of Scanning Electron Microscopy of MPEG, through an electron microscope LEO model 1450 VP. Regarding morphology, it is observed that there is a variety in the distribution and shape of the spines. The spines can present elongated and short, straight and recurved forms that occur in the same individual and in different regions. Regarding the anatomical aspects, it is noticed that in O. polyacanthos the pinnules present epidermal cells of the abaxial surface similar to the adaxial one; the epidermal appendages are denser in the abaxial one. They have a tetracyclic stomatal complex and the leaves are amphiphyllous and the trichomes are bifid pluricellular. The epidermis is covered by a slightly thickened cuticle, followed by a thin-walled, irregular hypodermis. The mesophyll consists of poorly differentiated chlorenchyma with irregular and juxtaposed cells, interrupted by fibrous bundles lined up towards the margin. The vascular bundles, in all regions, are collateral, some with bipartite phloem, partially or totally involved by fibrous clusters and a parenchymatous sheath. In the stem there is an extensive fibrous sheath surrounding the vascular bundles. In the root there is amyliferous parenchyma, aerenchyma of lysigenous origin and lateral roots originating from the pericycle. It is noticed that the species has specific characteristics and great presence of fibers in the stem, thus justifying its use for various types of handicrafts.