The determination of the ecological condition of wetland and riparian habitats has been the focus of research by many scientists, because of the importance to understand the processes and related functions of these systems. Research on montane wetland and riparian systems has shown the relative importance of native aquatic plants in maintaining these systems in a functional condition. The presence or absence of key species is used as an indicator of the ecological condition, and desired ecological condition of wetlands and riparian habitats can be expressed in terms of the species composition and abundance of native aquatic plants. This type of information is needed by resource managers in defining the endpoint of their management actions. Information is presented on the functional role of these species in sustaining the biological and physical integrity of these habitats.