Vegetative and reproductive morphology varies considerably in the genus. Two types of stems occur, rhizomes and erect stems. Some species have both, others have only the erect stem. Two types of leaves exit, submersed leaves and floating leaves. These leaves may be similar in shape to that of the submersed leaves, or they may differ very much in shape.
Submersed leaves are without a cuticle and usually are without a well-developed epidermis.
All species have submersed leaves, whereas others also have floating leaves. Occasionally, individuals of floating-leaved species lose their submersed due to decay or way action. The leaves of Potamogeton may be sessile or petiolate and are divided into at least a blade and a stipule. Venation in the stipule is parallel, and the veins may appear coarse as distinct ridges on the stipule, in which case they are considered fibrous, or they may be much less obvious, even difficult to observe, in which case they are considered to be delicate. Stipule tissue between the veins of fibrous stipules usually decays, leaving strands of fibers, whereas the tissue between the veins and the veins decay in delicate stipules.