Environmental & Extension Services Department - Pest Management Division
Common Aquatic Weeds
Identification of aquatic plants, those growing in the water, is vital to our Aquatic Inspector/Sprayers. Correct identification is necessary to select the proper herbicide for control of the particular weed. Aquatic plants are grouped according to the following growth habits:
Submersed - Plants growing completely below the water surface and dependent on the surrounding water for support of the plant body.
Emersed – Plants rooted in the bottom, extending above the water surface and are self-supporting.
Floating – Plants not attached to the bottom, they float on the water surface.
Floating leaf – Plants are attached to the bottom and have leaves that float on the water surface. They may or may not be self-supporting and can also be emersed.
Algae – Single-celled or multi-celled plants that lack true supporting or conducting tissues. They are submersed weeds. Examples include Spirogyra, Chara, muskgrass, and stonewort.
Ferns – Large, conspicuous plants with true supporting and conducting tissues that do not flower or produce seeds. They are typically floating weeds. Examples include water fern and mosquito fern.
Grasses, Sedges, & Rushes – They are emersed, sometimes submersed, flowering plants. They may have underground stems, runners, or can root at the point of leaf attachment. Some species may occur on the shoreline, as well. Examples include torpedo grass, maidencane, bulrush, and spikerush.
Frogbit family – They are floating and submersed plants. Some plants in this family are exotic and nuisances. Examples include frogbit, hydrilla (exotic, nuisance), Brazilian elodea, and American eelgrass.
Pickerelweed family – These plants can be emergent or shoreline plants with thick, creeping roots (pickerelweed) or a floating plant (water hyacinth). Examples include pickerelweed and water hyacinth (exotic, nuisance).
Arum family – Floating plants. Water lettuce is an exotic, nuisance species. Mosquito larvae are sometimes found on the underside of the leaves and attached to the roots.
Duckweed family – These are small, floating plants that reproduce quickly to cover the water surface. Examples include common duckweed, giant duckweed, and common watermeal.
Cattail family – They are emergent plants that arise from thick underground stems. They may reach 10 feet tall. They can quickly become a nuisance, clogging water bodies.
Waterlily family – These plants are floating leaves that are attached to elongated stems rooted in the soil below. Examples include waterlily and spatterdock.
For more information
Charlotte County Environmental & Extension Services
25550 Harbor View Road, Unit 2, Port Charlotte, FL 33980
941.764.4360
