Anatomia dos órgãos vegetativos de paragonia pyramidata (rich) bureau (bignoniaceae)

Abstract

Paragonia pyramidata is a tropical liana very common in Amazonian forests, inhabiting large trees. In the restinga of Algodoal/Maiandeua Islands in the Environmental Protection Areas (APA) characterized as restinga ecosystems, this species is found on dunes forming one of the first vegetational strands near the ocean. In the literature there are few studies of plant anatomy in this type of ecosystem, so we studied the anatomy of the vegetative organs of this species. For the anatomical analysis, the material was fixed in alcohol 70%, for further execution of the techniques of dissociation of the epidermis, diaphanization and transversal sections of the leaflet, stem and root. The histological analysis of the leaf blade, in frontal view, shows that the species is hypoestomatic, with glandular trichomes on both sides. Diaphanization indicates a brochydromous pattern. In cross sections it was noted that the leaflet is dorso-ventral, with a hypodermis formed by colorless cells, larger than the epidermal cells. The vascular bundles are collateral and dispersed in the mesophyll, which are protected by a fibrous sheath. The petiole has a vascular ring, where at the phloerna level a fiber cap occurs. The root, when young, presents a secondary structural configuration, where we can distinguish three distinct regions: a secondary lining region (periderm), a cortical region with cells rich in starch and a vascular region where the vessel elements are involved by fibers. The stem, on the other hand, also in cross section, presents two distinct regions, one of secondary lining (bark), followed by the region formed by simple pores and in it growth rings can be distinguished. The anatomical structure found in this species allows us to consider it well established in the restinga ecosystem