Submersed Plants
Submersed plants are rooted at the bottom of water bodies and are entirely underwater. These plants typically have a flexible, flaccid structure due to the absence of rigid cellular tissue. If present, their flowers may extend above the water surface.
Bushy Pondweed (Najas Gracillima)
Bushy Pondweed may be mistaken for Chara or Coontail, but it can be distinguished by its lack of musky odor when crushed, which Chara has. This plant features narrow leaves with tiny spines along the edges and slender stems that branch frequently. The leaves are densely concentrated at the tips, arranged oppositely or in groups of two or more at each node.
American Pondweed (Potamogeton Nodosus)
American Pondweed is a perennial aquatic plant characterized by its alternating floating and submerged leaves. The floating leaves are elliptical to oval in shape, ranging from 4 to 7 inches in length and up to 1 inch in width, and are attached to long petioles. The submerged leaves are less abundant, blade-like, somewhat transparent, and smaller than the floating leaves.
Cabomba (Fanwort) (Cabomba Caroliniana)
Cabomba, commonly known as Fanwort, is a multi-branched submerged perennial plant distinguished by its few small, elongated floating leaves measuring ½ to 1¼ inches in length. The submerged leaves are opposite each other, attached by a single petiole, and are finely divided into a “fan-shaped” form. Cabomba produces small white to pink flowers, ½ to ¾ inch in diameter, which emerge from the tip of the stem and extend slightly above the water’s surface.
Coontail (Ceratophyllum Demersum)
Coontail is characterized by its serrated leaves and the varying spacing between leaf whorls, which become more crowded at the tips. The plant features branches that fork repeatedly. While it may be confused with Bushy Pondweed or Chara, Coontail is distinguishable from Chara by the absence of a musky odor when crushed.
Eurasian Watermilfoil (Myriophyllum Spicatum) *
Eurasian Watermilfoil is a perennial aquatic plant native to Europe, Asia, and Africa, and was likely introduced to the U.S. as an aquarium plant. It is now recognized as one of the most aggressive and problematic aquatic plants in the U.S. due to its ability to form dense colonies. The plant features multi-branched stems that are somewhat reddish in color, with gray-green feather-like leaves. The leaves are arranged in whorls of 3 to 5 around the stem and are divided into 12 or more pairs of thin, thread-like leaflets. Reddish flowers appear on leafless spikes that extend a few inches above the water’s surface. Eurasian Watermilfoil can spread through both seeds and fragmentation.
Hydrilla (Hydrilla Verticillata) *
Hydrilla is a perennial aquatic plant known for its ability to form dense colonies and grow to the surface in water over 20 feet deep. It branches profusely and, upon reaching the surface, spreads out to form thick mats. Hydrilla can reproduce through fragmentation, seeds, turions (axillary buds), and tubers. The leaves are blade-like, measuring about ⅛ to ⅜ inch in length, with small tooth margins and spines on the underside of the midrib, giving them a rough texture. Typically, leaves are arranged in whorls of 4 to 8.
Native to Europe and Asia, Hydrilla was likely introduced to the U.S. through the aquarium industry. It is considered a noxious pest due to its rapid growth, which allows it to outcompete and eliminate native species, and create surface mats that obstruct recreation, navigation, and water intakes.
Parrotfeather (Myriophyllum Aquaticum) *
Parrotfeather, originally native to South America, was likely introduced to the U.S. through the aquarium industry. It is a rooted, submerged perennial plant that typically thrives in shallow water. The plant is distinguished by its gray-green, thickly bunched leaves that rise above the water’s surface, giving it a feather-like appearance. These exposed leaves are arranged in whorls and feature frilly divisions. The underwater leaves resemble the above-water ones but are less dense. The stems of Parrotfeather are relatively stiff.
Although Parrotfeather is not native to North America, it has become naturalized in many parts of the United States. While possessing Parrotfeather is not illegal in Texas, it is advisable not to introduce this plant into new water bodies to prevent potential ecological impacts.
*: TEXAS RESIDENTS: THIS PLANT IS NOT NATIVE TO NORTH AMERICA AND IT IS ILLEGAL TO POSSESS OR TRANSPORT THIS SPECIES IN TEXAS. PLEASE REPORT SIGHTINGS OF THIS PLANT TO THE TEXAS PARK AND WILDLIFE DEPARTMENT.
