Which plant is categorized as a federal noxious weed?

The classification of a plant as a federal noxious weed indicates that it poses a significant threat to agriculture, horticulture, natural resources, or the economy at the national level. Among the choices provided, Eurasian Watermilfoil is recognized as a federal noxious weed due to its ability to rapidly reproduce, create dense mats in water bodies, and disrupt native aquatic habitats. These characteristics make it a problematic invasive species in various regions.

Common elodea, duck-lettuce, and watergrass also have implications for aquatic environments, but they do not hold the same level of federal noxious weed status as Eurasian Watermilfoil. Understanding which species are classified in this manner is crucial for developing effective management and control strategies to protect native ecosystems from these invasive plants.