The pollen morphology of six species of aquatic angiosperms from
Saudi Arabia belonging to five genera distributed in five families was
examined using both light and scanning electron microscopy. Based on apertural
type, three distinct pollen types are recognized. Pollen Type-I is characterized
by its non-aperturate pollen such as Elodea canadensis, Potamogeton
crispus, P. pectinatus and Ruppia maritima. Pollen Type-II
is easily recognized by having porate pollen such as Lemna gibba.
Pollen Type-III is readily delimited by having colpate pollen such as
Myriophyllumspicatum. The correlation between pollen morphology
and pollination mechanism is discussed.