When attempting to manage and control invasive Phragmites, it is important to first determine if the plants you are managing are the native or invasive strain of Phragmites. Native Phragmites is an important component of a healthy wetland ecosystem. It grows in marshes and unlike the invasive strain, does not typically develop into dense monocultures or degrade habitat quality. There are certain morphological differences that do exist between the native and invasive Phragmites, which can help determine what strain you are dealing with.