Pistia stratiotes in China
Pistia stratiotes (Araceae: EPPO A2 List) is a free-floating perennial freshwater macrophyte native to South America. The species is invasive in many regions of the world including Africa, Asia, Central America and the Caribbean, North America, and Oceania. P. stratiotes was introduced into China over 500 years ago. It was originally utilised as a medicinal plant for an array of ailments, and more recently has been used as a food plant for livestock and as a plant for water purification. It can now be found in 21 provinces in China and occurs in a broad range of aquatic habitats including slow-moving rivers, ponds, reservoirs, lakes and paddy fields. In these habitats, P. stratiotes forms dense monocultures which can have a negative impact by reducing native submerged plants by blocking light and oxygen exchange. It can also have negative impacts on ecosystem services in China, by threatening food production (e.g. in rice paddies) and water movement and quality. Regions where P. stratiotes is most invasive in China support over 70 % of the countries agriculture production. In addition, P. stratiotes can act to reduce fisheries catches and increase the abundance of infectious mosquito-borne diseases by forming suitable resting habitats.