CARACTERIZACIÓN ANATÓMICA DE LOS ÓRGANOS VEGETATIVOS DE Oxycarpha suaedifolia S. BLAKE (ASTERACEAE), ESPECIE ENDÉMICA DE LA PLANICIE XEROFÍTICA COSTERA DEL ESTADO FALCÓN (VENEZUELA)

Abstract

Oxycarpha suaedifolia, is a little known endemic species, which is distributed geographically from Cuare Reserve to the lower basin of the Mitare River, Falcon State, Venezuela, where the prevailing environmental characteristics are: high exposure to sunlight, high temperatures, low rainfall, and dry saline soils. We studied the anatomy of vegetative organs in order to provide information and identify biological characters of adaptability to soil and climatic conditions prevailing in the area where it grows. In this species there are two types of adventitious roots, a thin one (< 1 mm diameter) with a bi- or triarch stele, and another, of larger diameter (± 2mm), which is characterized by preserving its primary structure, even in areas away from the apex and has hexarc strongly sclerificated xylem, and is associated with mycorrhizae. Orthotropic stems in their basal portions are anatomically similar to the stolons, being evident in both the presence of voluminous cork cells and cortical aerenchyma, as well a secondary vascular system in a sinuous arrangement. The leaves are succulent, amphistomatic and equifacial. This species has, in its vegetative organs, anatomical features that confer adaptability to environmental conditions existent in the area where it grows.