Anatomía de Nitrophila australis Chodat & Wilczek var. australis, una halófila endémica argentina

PÉREZ CUADRA, V.; HERMANN, P.

Tandil, Pcia de Buenos Aires

Congreso; 10° Congreso Argentino de Ciencias Morfológicas; 2006

Universidad Nacional del Centro de la Provincia de Buenos Aires

The anatomy of Nitrophila australis, a rhizomatous species of the Chenopodiaceae, was studied since few such studies of representatives of this family have been made. It is found in the Salitral de la Vidriera (Buenos Aires). The leaves have large epidermal cells, there is abundant cuticle and the stomata are superficial and anomocytic. The chlorenchyma has no particular characteristics, being of smaller cells than the parenchyma which surrounds the vascular bundles; there are druses in both tissues. There is a large central vascular bundle and six smaller ones on each side. All of them have xylem, phloem and a cap of collenchyma cells next to the phloem. The stem epidermis is similar, beneath which exists a layer of angular collenchyma. The cortical parenchyma has large intercellular spaces, and druses in some cells. A layer of collenchyma surrounds the stele, forming caps in some of the bundles and sheaths in others. The stele is made up of four vascular bundles, two large and two small, placed in pairs. The phellogen in the rhizomes is superficial, producing middle-sized cork cells with slightly thickened cell walls. A large number of starch grains and a few druses are found in the cortical parenchyma. Small groups of fibres are sometimes present outside the primary phloem. The stele is formed by a variable number of vascular bundles. These characteristics are unlike those found in similar halophyte genera of the Chenopodiaceae.