Potamogeton gramineus is a species of aquatic plant known by the common name various-leaved pondweed, variableleaf pondweed, grass-leaved pondweed or grassy pondweed, native to the northern hemisphere where it grows in shallow, clean water. Potamogeton gramineus is native to much of the Northern Hemisphere, with a Holarctic distribution. It occurs in northern Europe (Britain, Ireland, Iceland, Scandinavia, Germany, Switzerland, France, Poland, Russia, the Baltic States), Greenland, North America (USA except for the southeast, Canada). There are outlying populations in southern Europe (Iberia, Corsica, Italy), Caucasus, Pyrenees and western USA. This is an aquatic perennial growing from a creeping rhizome that anchors in wet substrate. It produces thin, cylindrical, heavily branching stems usually less than a metre in length.