Alien invaders: The invasive plant species wreaking havoc in our area

Alien invaders: The invasive plant species wreaking havoc in our area

Looks can only carry you so far. 

Water hyacinth

Just being beautiful isn't enough to make certain plants welcome in Texas.

Across the Brazos River basin, there are plants that have entered our watershed and are destroying ecosystems, stealing water, causing harm to native species, and hindering recreation.

The most common invasive plants include alligatorweed, Chinese Tallow Tree, hydrilla, giant salvinia, kudzu, saltcedar and water hyacinth. 
Invasive species, which can be plants or animals, are not native to a particular area and can cause economic and ecological damage and impact human health. It's easy for them to do because once non-native species are introduced to an area, they have few natural predators, competitors, or diseases that regulate their populations.

"Nationwide, the annual economic impact of all invasive species in the U.S. has reached approximately $219 billion, with global impacts estimated at over $4 trillion," according to the TPWD in an April 2021 release. "Aquatic invasive species are among the worst of these, requiring considerable effort to prevent, monitor for, and effectively manage and mitigate infestations when possible. In response to this need, for the past five years — since the state's fiscal year 2016 — the Texas Legislature has allocated approximately $3.2 million per year to combat aquatic invasive species in Texas."

The Brazos River Authority's environmental services department regularly monitors different plants as a way of tracking the health of the Brazos River basin ecosystem. When the results show changes, the BRA and state and federal partners work to identify the cause. Once a cause is identified, work can be done to make improvements that can aid the continued health and quality of the basin's water supply.

Here are some highlights on Brazos basin invasive species:



  • Forms thick mats that crowd out native aquatic vegetation, reduce water flow, lower dissolved oxygen levels, and increase sedimentation.
  • Can cause flooding by impeding drainage and restricting water flow for irrigation.
  • Spreads rapidly and is difficult to remove.

Chinese Tallow Tree

  • Tremendous reproductive potential, it can annually produce an average of 100,000 seeds.
  • Nearly impossible to eliminate once established.
  • Mainly placed for its unique ornamental qualities, including colorful, autumnal foliage.


  • Named after Hydra, the nine-headed serpent of Greek mythology.
  • Can grow an entirely new plant from a tiny stem fragment.
  • Dense mats of Hydrilla can alter water chemistry, cause dramatic swings in dissolved oxygen levels, increase water temperatures and affect the diversity and abundance of fish populations.

Giant salvinia

  • A floating fern from Brazil.
  • Can damage aquatic ecosystems by outgrowing and replacing native plants that provide food and habitat for native animals and waterfowl.
  • Infestations can double in about a week under the right circumstances.


  • Kills or degrades other plants by smothering them under a solid blanket of leaves.
  • Thought to have been brought into the state to help stabilize erosion along riverbanks or as a decorative garden plant.
  • Capable of growing at an alarming rate of up to 1 foot a day.


  • Got its name because it oozes salt from its leaves.
  • Can consume large quantities of water, reducing the amount of water available for other plants, animals and humans.
  • Can have pale pink or white flowers and fruit and have long tap roots that allow them to intercept deep water tables and interfere with natural aquatic systems.

Water hyacinth

  • Floats on water and can spread from fragmentation and seed production.
  • Can produce thousands of seeds a year that can be viable for up to 30 years.
  • Thick layers of hyacinth could also interfere with boat navigation and recreational activities.

Help stop the spread of invasives. Always:

  • Clean mud or plant fragments from the boat, propeller, boat trailer and all gear, including waders and boots, before leaving a water body. 
  • Drain all the water from the boat, including the bilge, live well, motor, and trailer, tackle and gear before leaving the area.
  • Dry the boat trailer and gear after each use.
  • And never release aquarium or water garden plants into the wild. Instead, seal them in a plastic bag and throw them in the trash.

Early detection is crucial to stopping the spread of invasive species. Reporting sightings to Texas Invasives.