Anatomia foliar de Blechnum serrulatumRich. (Blechnaceae — Monilophyta) do Horto Florestal Olho D'água da Bica, Cuité-PB.

Abstract

Ferns are a very ancient plant group, considered to be the first to conquer the terrestrial environment due to the presence of vessels conducting water and nutrients. Although, today it is still a poorly understood group in relation to its anatomy where most of the existing works are based on Íloristic surveys. It is a group of great taxonomic significance for maintenance of environment's humidity. Few studies show the Caatinga ferns and this amount decreases when it comes to Blechnaceae family and more so when restricted to the state of Paraiba. The Tree Farm of OlhoDoágua da Bica in the city of Cuité-PB is & remaining area of Caatinga previously disturbed by human activities and grazing, has less than five years in the process of natural restoration. It consists of high biodiversity, which number of species requires urgent studies in order to characterization.The objective is then to study the leaf anatomy of the Blechnum serrulalum Rich species. (Blechnaceae — Monilophyta) since it was found in relative amounts and restricted to a single point of the chosen area. For the morphological and histochemical analysis were used Johansen (1940) techniques. The Blechnum serrulatum Rich.species presented glabrous epidermis throughout frond with small scales spaced along the coast. In the pinnae, epidermal cells showed irregular shapes, with very sinuous walls, stomata restricted to abaxial surface, anficrivais beams of the "seahorse" type in the midrib, homogeneous mesophyll with uniseriate epidermis and thin cuticle. At thestipes, the spinal cord region is formed by aerenchyma, vascular bundles are of the Aspidium type surrounded by endoderm containing Caspary's grooves and parenchymatous sheath filled with phenolic compounds and strongly lignifled sclerenchyma of braquiesclereide type. This study of leaf anatomy of Blechnum serrulatum Rich.will help to distinguish this species at microscopic level since it brings important diagnostic characters that will allow a better understanding of the taxonomic species.