Potamogeton praelongus, commonly known as whitestem pondweed in North America and Long-stalked Pondweed in Britain, is a large, perennial aquatic plant in the family Potamogetonaceae. It is widely distributed in lakes and rivers in the northern hemisphere, but is sensitive to poor water quality.
Long-stalked pondweed has tall stems to 3 m growing from stout, rusty-spotted perennial rhizomes. The stems often change direction between each node, giving a characteristic zig-zagging pattern. The transparent ...