VARIANTE EN LA ACTIVIDAD DEL CAMBIUM VASCULAR EN TALLOS DE Sesuvium edmonstoneii Hook. f. (AIZOACEAE)

Abstract

The secondary growth that takes place in stems of Sesuvium edmonstoneii, a halophytic species that grows in the coastal zones of Falcon state (Venezuela) was observed in order to study the cambial variant that occurs in them. The study was carried on segments of stems with different diameter, fixed in FAA and prepared according to the classic techniques for optical microscopy. The results reveal the formation of successive rings of vascular tissue originated by a master cambium produced by divisions of parenchymatic cells. This meristem produce conjunctive tissue and vascular cambia segments, they produce groups of xylem and phloem. The presence of thick cuticle initially and then the development of peridermis with multiple strata, as well as the abundance of starch are features that can be associated with the survival capacity of the species. It is likely that the voluminous epidermal cells, the abundant parenchyma, and the concentric rings of vascular tissue contribute to water and photosynthates storage. All of these features may facilitate the presence of this species in its natural habitat.