various species of Typha prefer different water depth and water depth fluctuation. Cattails very often invade natural wetlands and displace native species. Also, when planted in constructed wetlands, they tend to out compete other species planted in the wetland. The most frequently used species in FWS CWs is T. latifolia L. (Common cattail,Broad-leaved cattail) which has been reported within the survey in 320 CWs from all continents except Central and South America