Alligator Weed

Alligator weed (Althernanthera phyloxeroides) forms very dense stands or mats that make shoreline access difficult. It has hollow aquatic stems that can be single or branched and are green or reddish purple. Leaves are arranged opposite of each other along the stem, and are long and lance-shaped. Often roots develop at leaf nodes. Single flowers are small, white, and fragrant in clusters of 6 to 10 florets. Alligator weed is generally rooted along the shoreline, but can detach from the shoreline to form a floating mat of erect stems.

Alligator weed forming a dense mat along the shoreline

Management Options

Mechanical Options

Alligator weed can be cut and removed from the pond.

Mechanical treatment of aquatic vegetation

Biological Options

There are no biological options for controlling alligator weed.

Chemical Options

The active ingredients that have been successful in treating alligator weed include: 2, 4-D (G), Fluridone (G), Glyphosphate (G), Imazamox (G), Imazapyr (E), and Triclopyr (E). E = excellent, G = good

Chemical treatment of aquatic vegetation

Return to the emergent vegetation page