Laticifer systems in Mandevilla illustris and M. velutina apocynaceae

Abstract

Two <em>Apocynaceae</em> species from savanna (Cerrado) area of Sao Paulo State, Brazil were studied. In both Mandevilla species examined, the laticifer systems are of non-articulated branched type, characteristic of the family. In vegetative organs reported was the occurrence of a primary laticifer system of which the cells were differentiated in the embryo. However, additional laticifer cells were always produced during the growth of the shoot apex. A secondary laticiferous system produced by the cells of vascular cambium was identified in the tuberous root and in the stem. A proposed discussion on this apparently unique record in <em>Apocynaceae</em> was arisen to evaluate the main distinction between articulated and non-articulated laticifers.