Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.
Pistia stratiotes is an aquatic plant with a world-wide distribution. Its native range is not well described. The history of invasiveness is high. There are records of known introductions and negative impacts to both biodiversity and human health where this species establishes large colonies. Established populations of P. stratiotes reduce native plant species, lower the dissolved oxygen under mats to below critical levels, and inhibit recreation uses such as boating and swimming. The mosquito carriers for St. Louis Encephalitis use the roots of this plant during reproduction. Climate matching indicated the contiguous United States has a high climate match with established P. stratiotes populations. The certainty of assessment is medium. The overall risk assessment category is high.
Publication date
Type of document
High Risk
Program
