Virginia Tech Weed Identification Guide

Slender or Small Pondweed: Potamogeton pusillus

Weed Description:  A submersed aquatic perennial weed with narrow, ribbon-like leaves that often forms thick mats, especially in shallow water.  Slender pondweed is found in lakes and ponds throughout the southeastern United States.

Stems:   Root at the nodes when in contact with the ground.

Leaves: Leaves are arranged alternately along the stem and are linear or ribbon-like in outline, approximately 1 to 2 inches long and only a few millimeters wide.  A pair of glands occurs at the bases of the leaves, which are often difficult to see with the naked eye.  The leaves also have stipules that are separate from the leaf bases and are approximately 1/3 to 2/3 inch long.

Flowers:  Small flower spikes occur on short stalks (peduncles) that arise from the area between the leaf bases and the stems.

slndrpndweed8-8.jpg (116201 bytes) Fruit:  An achene.

Identifying Characteristics:  The alternately arranged narrow, ribbon-like leaves and stipules are both characteristics that help to distinguish this weed from other aquatic plants.  Slender pondweed is often confused with southern naiad (Najas guadalupensis), however the leaves of this aquatic are arranged oppositely along the stem and have toothed margins unlike those of slender pondweed.