This particular plant is widely known as the “common reed,” but the havoc it is causing on wetlands in various parts of the United States is anything but, which is why it definitely makes our list of the worst water weeds. In the world of scientific botany, the genus is known as Phragmites, with four main species found in different parts of the world. Only one of those four species, however, is the one causing major headaches around the country. It is also on the list of Invasive and Exotic Aquatic Plantsmaintained by the Center for Invasive Species and Ecosystem Health. Here’s what you need to know about Phragmites.