Thickening of aerial roots of Pandanus Parkinson (Pandanaceae) species

Abstract

Monocotyledon roots and stems are organs that usually do not show secondary growth or thickness. However, it can occur and for the roots, the literature does not provide much information. Species of the genus Pandanus are easily found in urban areas and are characterized by the presence of thickened aerial roots, originating from the stem. To verify how thickening occurs, roots of P. utilis Bory, P. baptisti Hort., P. amaryllifolius Roxb e P. veitchii Hort samples of the roots were collected in urban areas, fixed and processed according to the usual technique for analysis under a light microscope. For all species, thickening occurs in the acropetal direction, through the formation and expansion of spaces of intercellular spaces in the cortex and in the vascular cylinder, meristematic activity of the proendodermis, division and increase in volume of the parenchymatic cells of the cortex and the vascular cylinder and meristematic activity of the pericycle.