Pollen Morphology of Plantago species native to Saudi Arabia and their taxononomic implication

Pollen grain morphology of 6 Plantago species of the family Plantaginaceae collected from Saudi Arabia have been observed under light and scanning electron microscope (SEM). Description of grain sculpture is illustrated by SEM. Plantaginaceae is a stenopalynous family. Pollen grains are free, medium-sized or small, radially symmetrical, apolar, porate, spherical or prolate spheroidal in shape with verrucate granulated sculpturing. Internal aperture has pores scattered on the wall of pollen grains. Identification feature of individual taxa include type of aperture, ornamentation of the pollen grain, annulus structure and pore diameter. The pollen morphology of the family Plantaginaceae is significantly helpful at specific level. On the basis of exine ornamentation 2 distinct pollen types viz., Plantago – major and Plantago – vate – type are recognized