Aquatic Weed

Alligator Weed

Alligator weed (Alternanthera philoxeroides), non-native. emerges from shoreline and near-shore areas in spring, vertical stems begin to spread along the water’s surface, forming an interwoven mat.

American Lotus (Nelumbo lutea), a native species, will grow rapidly through the summer. Large colonies of the plant will form along the shoreline with some leaves floating and others standing high above the water resembling a tuba.

American Pondweed

American pondweed (Potamogeton nodosus) is among the first grass to emerge from waterways, popping up in late April and early May. Waterfowl enjoy eating seeds from the native plant, but dense growth can impact water use.

Arrowhead

Arrowhead (Sagittaria sp.), native. takes its name from its distinctive shape. Arrowhead plants have long grown in the Tennessee Valley region.

Brazilian Elodea

Brazilian elodea (Egeria densa), a non-native plant acts much like an evergreen, coming back from existing plants in the spring. It grows fast, creating dense, tangled mats on the water’s surface.

Brittle Naiad

Brittle naiad (Najas minor), a non-native species, prefers to grow within stands of other vegetation. It is often found intermixed with other species, often resembling bright green clumps.

Canadian Elodea

Canadian elodea (Elodea canadensis) emerges in early spring from overwintering buds. While this native species is not as aggressive as other plants, its growth increases in the summer.

Common Cattail

Waterfowl and other shoreline birds eat the seeds of the native common cattail (Typha latifolia) and use the plant for nesting.

Coontail

Native coontail (Ceratopyllum demersum) gets its name from its appearance. It absorbs nutrients from the water, helping improve water clarity in some cases, and provides food and water for fish and wildlife.

Curlyleaf Pondweed

Curlyleaf pondweed (Potamogeton crispus), a non-native plant, can thrive in areas with low water clarity. It emerges in early spring and blooms in June.

Duckweed

Duckweed (Lemna minor), native, is also known as water lentils or water lenses. This plant floats on or near the water’s surface.

Eelgrass

You will find two types of eelgrass in the Valley region, native Vallisneria americana and non-native "Rockstar" Hybrid (V. spiralus x V. densaserrulata). Eelgrass provides food and shelter to fish, waterfowl and sea turtles.

Eurasian Watermilfoil

Eurasian watermilfoil (Myriophyllum spicatum), a non-native species can be a key resource for waterfowl in the Tennessee Valley region, not because of its nutritional value, but because of its abundance.

Fanwort

In fall, native fanwort (Cabomba caroliniana) mats seem to persist longer than those of native annuals like slender pondweed and southern naiad.

Fragrant Waterlily

In early spring, patches of freshly sprouted fragrant waterlily (Nymphaea odorata), a native plant, can be some of the only vegetation actively growing in the area.

Frog's Bit

Frog's Bit (Limnobium spongia), a native plant, will likely go unnoticed in spring as the perennial grows back from overwintering buds, floating to the water surface to sprout new growth. Mature plants provide perfect cover for bass to ambush their prey.

Giant Cut Grass

The large seed head of the native giant cut grass (Zizaniopsis miliacea) releases seed into the water during fall as leaves will begin to die off and decay.

Hydrilla

Two types of non-native hydrilla (Hydrilla verticillata), D-hydrilla and M-hydrilla, have different growth habits but will both eventually form dense canopy mats during the summer.

Mosquito Fern

Mosquito Fern (Azolla caroliniana), native. may not be visible to the naked eye during early growth. Colonies become more apparent by late summer, growing thicker through fall.

Muskgrass

Native muskgrass (Chara sp.) can be finicky in growth cycles, seeing boom and bust years. When in a “boom” year, muskgrass will likely be one of the first species to begin growing.

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We're always looking for more information about aquatic plants on TVA reservoirs. Let us know where and what you see, and send us your photos. Email us.

Curlyleaf Pondweed

Curlyleaf pondweed (Potamogeton crispus), a non-native plant, can thrive in areas with low water clarity. It emerges in early spring and blooms in June.

Parrot Feather

Non-native parrot feather (Myriophyllum aquaticum), a non-native plant grows well in calm, cool water. Introduced through the aquarium trade, this plant can be found in at least 26 states throughout the United States.

Water Stargrass

Water Stargrass (Heteranthera dubia) Bright yellow star blooms just over the water surface make water stargrass easy to identify.

Arrowhead

Arrowhead (Sagittaria sp.), native. takes its name from its distinctive shape. Arrowhead plants have long grown in the Tennessee Valley region.

Watermeal

Watermeal (Wolffia columbiana), is a native species. Individual plants are barely visible to the human eye, but colonies can cover the water’s surface.

Duckweed

Duckweed (Lemna minor), native, is also known as water lentils or water lenses. This plant floats on or near the water’s surface.

Southern Naiad

Native southern naiad (Najas guadalupensis) will increase growth and begin to top out during summer. Reaching the surface, the plant will begin to flower and continue to bloom through fall.

Slender Pondweed

Slender pondweed (Potamogeton pusillus), a native plant, will begin dying back early in fall, opening up space between other plants.

Sago Pondweed

Native sago pondweed (Potamogeton pectinatus) is among the first grass to appear in the spring. Waterfowl rely on it for food, consuming the whole plant.