Características morfológicas e anatômicas das folhas de urospatha caudata (poepp. et endl) schott (araceae), ocorrentes em áreas de várzea e igapó

Abstract

Urospatha caudata (Poepp. Et Endl) Schott, an aquatic macrophyte occurring in várzea and igapó. This work aims to compare the morpho-anatomical characteristics of the leaves of specimens from várzea and igapó. Fresh material was collected from the Mocambo Reserve in Belém and Marapanim. Epidermal dissociation and cross-sections of the leaf lamina were performed, according to usual procedures of plant anatomy, staining them with Astra and Safranin blue. The leaves of the igapó specimens presented leaf lamina and petiole larger than those of the várzea specimens. The cuticle, in frontal view, is wavy, thickened, on both sides, and on the main veins the undulations increase; and in cross section it is striated. The two epidermis, in frontal view, are formed by heterodimensional cells and on the main veins is isodiametric rectangular. In cross section the epidermis is rounded at the margins and in the other regions are rectangular. The paracitic stomas, in the apical region, occur in the same proportion in both epidermis, and in the abaxial one half are teratic, in the intermediate region paracitic stomas predominate in the abaxial epidermis, and in the adaxial margin paracitic stomas are rare, with reduced ostioles and in the abaxial absent. The mesophyll is formed by two layers of paliçadic, lacunose parenchyma characteristic of aquatic plants with evident aerenchyma, angular collenchyma in the main vein, collateral bundles of different sizes with xylem formed by tracheids. The petiole is evidenced by large aerenchyma with diaphragms and peripheral vascular bundles.