Pollen studies on some species of the genus Convolvulus L. (Convolvulaceae) from Morocco

Abstract

The pollen grains of nine species of Convolvulus L. from Morocco were studied using scanning electron microscopy and light microscopy. The species belong to three sections and four subsections: sections Convolvulus, Acanthocladi Boiss, and Inermes Boiss, and subsections Convolvulus, Spinescentes Boiss., Oleifolii Peter, and Diffusi Boiss. The pollen grains in the genus examined are all 3-zonocolpate. The pollen is suboblate, oblate-spheroidal, prolate-spheroidal and prolate. The nexine is thinner than the sexine and the tectum is distinctly perforated in all species. The pollen grains show variation within the genus in polar and equatorial axes. colpus length and shape. These variations sometimes correspond with the morphological features of the species and, therefore, can be used to distinguish between some closely related species.