About Potamogeton natans L.
Potamogeton natans L. produces both floating and submersed leaves on a single individual. Its floating leaves are shaped ovate to oblong-ovate, and almost always have a cordate base. These floating leaves are dark green, leathery, and opaque, with translucent longitudinal veins. They measure 5 to 10 cm long, with pointed tips and rounded bases. The stipules of this plant are 4 to 17 cm long. The grass-like structures found submerged are called phyllodes, and are actually modified leaf stalks. The stems are cylindrical, have few branches, and reach 1 to 2 metres in length. The main distinguishing feature between Potamogeton natans L. and other pondweed species is a discoloured flexible joint located just below the top of the long leaf stalk. Its flower spikes are dense and cylindrical, measuring 5 to 10 cm long, with pointed tips and rounded bases. This species flowers from May to September. Its fruits are 4 to 5 mm long and obovate in shape.
