Características morfológicas e anatômicas de plântulas de laguncularia racemosa gaertn (combretaceae)

Abstract

The combretaceae family comprises about 18 genera and 450 tropical and subtropical species, among which Laguncularia racemosa Gaertn (Combretaceae), typical of mangroves, stands out. It is popularly known as white mangrove, inkwell among other names. It occurs on the coast of tropical, eastern and western America and has significant floristic importance in mangroves of the estuarine coastal region as in the Mujuim and Mocajuba River. The objective of this work was the morpho-anatomical characterization of L. racemosa seedlings in its different stages of development, relating them to the conquest of the saline aquatic environment, as well as its establishment in the coastal environment. Fruits and seedlings at different developmental stages were collected in the mangroves of São Caetano de Odivelas-PA. Histological cuts of the hypocotyl were made for the preparation of histological slides, according to usual techniques in plant anatomy, as well as dissection of flowers for a better knowledge of the species. L. racemosa generally presents a shrubby characteristic, simple, opposite obovate leaves with two glands situated in opposite disposition in its distal portion. The inflorescence is racemose with small, tubular, perfect or monoclinic flowers, pentamerous with an infertile ovary. In transverse section of the hypocotyl, cortical and medullary parenchyma rich in starch are observed. Rabinowitz (1978) states that the radicle is the first structure to attach itself to the soil; however, in the apical region of the hypocotyl there is no vascular system characteristic of a root.