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Wildlife & Fisheries Extension

Home / Fisheries / Aquatic Weed Control / Identifying Weeds

Aquatic Weed Control

Intro   |    Identifying Weeds   |   Controlling Weeds   |   List of Common Weeds   |   Control Methods


Identifying Weeds

Identifying a problem weed is the first step to controlling it. We have created an aquatic plant key as well as provided thumbnail photographs to assist you with weed identification. You can work through the key or glance through the thumbnail photos to identify a weed.

If you are unable to identify the weed through these methods, see the instructions for weed sample submission.

If you already know what the weed is, you may browse our list of common weeds for information on that plant.

Key to Common Aquatic Plants

This simplified key does not include all aquatic plants in Mississippi and is to be used to help you identify common problem aquatic plants only. You will be asked a series of questions about your unknown plant. Your answers to these questions will eventually provide you with the name of your weed and links to more information on this species as well as control methods for that plant. If you have trouble using the key or believe that the plant identification key has provided you with an incorrect identification for your aquatic plant, please consult your county agent for assistance.

What Does Your Plant Look Like?

Common Aquatic Weeds of Mississippi

Before browsing the thumbnail photos of common Mississippi aquatic plants, please select the category below in which your plant sample fits. These categories describe plant growth types. Read the growth type description to see where your sample fits and then click on that link to see images. This will help reduce the number of plant species you will examine. Click here to see a complete set of all common Mississippi aquatic plants.

Floating Plants

Floating Plants:include both free-floating plants not rooted or attached to the bottom soil and the floating-leaf plants with roots that attach to the bottom, stems extending toward the surface, and leaves that float on the surface. A few species may mature to have leaves that extend well above the surface, making them appear more like emergent plants. Likewise, some species of floating plants may appear to be submersed plants during certain seasons, growth stages, or under certain environmental conditions.

Below Water Plants

Submergent Plants: spend their entire life cycles at or below the surface of the water, although the flower parts of the plants may extend above the surface of the water. Usually the plants are rooted in the soil, but masses of plants may tear loose and float free in the water. Some submersed plants may appear to be emergent or floating plants, particularly when support structures for flowers are present. Some of the most noxious aquatic plants species are submersed.

Above and Below Plants

Emergent Plants: are rooted in the bottom soil and their leaves, stems, and flowers extend above the surface of the water. Many can grow in both aquatic and terrestrial environments. These plants are rigid and do not require the water for support. Many emergent plants may appear as submersed plants during the early growing season before they “top out,” and a few species may remain submersed indefinitely. In addition, a few may form extensive floating mats and, therefore, appear to be floating plants. Emergent plants are typically marginal except in water bodies that have extensive shallow water, or where they form mats that extend out to deeper water.

Submitting A Sample

If you are unable to identify the weed using our aquatic vegetation key and thumbnail photos, contact your county Extension office and work with Extension personnel to obtain assistance from an area agent or state specialist. You will need to submit a plant sample to your county Extension office in a zip-lock plastic bag.

  • The best samples include enough of the plant to reveal leaves, branches, roots, and flowers, if present.
  • The sample should be wrapped in wet paper towels or newspaper and then sealed in a zip-lock bag or other waterproof container.
  • Be sure to label the sample with your name, address, and telephone number.

If necessary, your county Extension personnel will submit the sample for identification to an area agent or state specialist in one of three ways.

  1. A series of digital images taken with a digital camera can be e-mailed to an area agent or state specialist.
  2. The plant will be blotted dry, laid out with branches and leaves spread, photocopied, and then this image will be faxed to the area agent or state specialist.
  3. When the previous two methods fail to produce an identification, an actual sample of the plant will be mailed to the area agent or state specialist.