Under the light microscope using 10x and 40x magnification, the pollen grains of grasses (monocots) appeared as monads with a single pore-type aperture (monopore), featuring an annulus and operculum. Their outlines in polar view were circular, sub-circular, or ovate. Most grass species had small pollen grains, while those of Zea mays ranged in size between 75–80 µm.

In dicots, the pollen grains exhibited coarse, wrinkled, and tectate exine structures. Their apertures ranged from triporate to periporate, with sizes varying from small to medium and large. The diversity in exine ornamentation among angiosperms was associated with various pollination mechanisms. Echinate pollen grains, for example, encourage bees to focus on nectar collection, which helps flowers conserve pollen for successful pollination. In contrast, smooth-walled pollen grains are typically associated with wind or water pollination.