Potamogeton americanusPotamogeton fluitans Potamogeton nodosus is a species of aquatic plant known by the common names longleaf pondweed[2] and Loddon pondweed.

[3] It is native to Eurasia and the Americas, where it is widespread and can be found in water bodies such as ponds, lakes, ditches, and streams.

This is a perennial herb producing a thin, branching stem easily exceeding a meter in maximum length.

The submerged leaves are linear to widely lance-shaped and up to 15 by 4 centimetres (5.9 in × 1.6 in) in length and width, respectively, while the floating leaves achieve shorter maximum lengths and are ovate or elliptic.

The inflorescence is a spike of many small flowers arising from the water on a peduncle.