Which invasive plant is known for producing dense mats on the water surface with leaves in whorls and a rough texture?

The choice of hydrilla as the correct answer is based on its distinctive characteristics and behavior in aquatic environments. Hydrilla is a submerged aquatic plant that is well-known for its ability to form dense mats on the surface of the water, particularly in nutrient-rich waters. One of its defining traits is that its leaves grow in whorls, typically with four to eight leaves per node, which gives it a dense appearance when it proliferates.

Additionally, hydrilla's leaves have a rough texture due to the presence of tiny, sharp edges, which can be identified by careful observation. This roughness, combined with the plant's growth habit, allows it to dominate water bodies and outcompete native vegetation, leading to significant ecological impacts.

Understanding the specific traits of hydrilla helps in managing its spread and the associated challenges it presents in Florida's aquatic systems.