A riparian invasive plant is an invasive plant growing in the vegetated areas next to watercourses (wetlands, streams, rivers, lakes, etc.) that protect water resources from pollution and provide bank stabilization and aquatic and wildlife habitat. Our native riparian vegetation has fine root hairs that bind the soil and provide stabilization to the bank, protecting the banks from erosion and hence, protecting water quality. Our native riparian vegetation also attracts specific insect populations that are part of the natural food web involving salmon, birds, amphibians, and other wildlife. When a stream becomes infested with a riparian invasive plant, such as Japanese knotweed, the entire ecological food web is disrupted, the banks are not stabilized as knotweed does not have the fine root hairs required to bind the soil, water quality is compromised, and access to the stream for recreational use is impeded. Other riparian invasive plants, such as yellow flag-iris and purple loosestrife, can eventually fill in wetlands or streams as they are fast growing, can outcompete with other wetland plants, and form almost impenetrable thickets with their thick rhizomes. As riparian areas are some of our most sensitive and productive habitats, their invasion by non-native plants can be devastating.