It is an extremely widespread species, reported across Europe, Asia, Africa, Australia, the Americas and many oceanic islands.
[3][4][5] Najas marina is an annual producing a slender, branching stem up to 40 or 45 centimeters in maximum length.
The evenly spaced leaves are up to 4 centimeters long, 1 to 3 millimeters wide, and edged in tiny sawlike teeth.
Populations declined in the 1960s because of pollution, but action has been taken to reduce the level of nutrients in the Norfolk Broads and the water quality has improved.
[11] One fossil seed of Najas marina has been extracted from borehole samples of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland.