Taxonomia e anatomia foliar da espécie paragonia pyramidata (l.rich) dc. bignoniaceae

Abstract

Paragonia pyramidata (L. Rich) DC. represents the Bignoniaceae family in the restinga of Algodoal and Maiandeua islands, municipality of Marapanim-Pará. In the tropics most species are lianas belonging to the tribe Bignonieae, one of the most important due to its diversity, frequency of occurrence and density. This work aims to study the morphology and anatomy of the species. The material for the study was collected on the islands of Algodoal and Maiandeua and fixed in 70% alcohol for later epidermal dissociation, diaphanization and histological sections. Paragonia pyramidata (L. Rich) De. is a liana of scandent habit, which has compound leaves, with leaflets measuring approximately 15 in, oblong, coriaceous, glabrous, acuminate apex, smooth margin and obtusely auriculate base. Anatomically, in frontal view, the leaf lamina is covered by a striated cuticle, with glandular trichomes on both sides and with stomas restricted to the abaxial side (hypoestomatic). In cross sections it was noted that the leaflet is dorso-ventral, with uni or biseriate hypodermis close to the adaxial epidermis, which is formed by colorless cells, larger than the epidermal cells. The epidermal cells, which are on the ribs, are quite elongated. The vascular bundles are collateral and dispersed in the mesophyll, which are protected by a fibrous sheath. The diaphanized leaf indicates that the network of veins follows a brochydromous pattern. The petiole shows a vascular ring, where at the phloem level a' fiber cap occurs. The structures observed in Paragonia pyramidata (L. Rich) De. present some characteristics common to the family and others peculiar to the species.