Identification: A perennial upright shrubby stream bank invader with a woody crown and stiff, 4-sided stems. Leaves opposite or whorled, small magenta flowers with 5-7 petals on tall showy spikes.
Impacts: Can quickly adapt to environmental changes and expand its range to replace native plants that waterfowl use for ground cover, food or nesting material. Spreads by stem fragments and reproduces by seed. One plant can produce over two million seeds.
Management: Small infestations can be dug up being sure to remove roots, monitor and repeat as needed. Plant parts can resprout. Seal in plastic bags and dispose in landfill. Biological control agents (weevils and beetles) help manage Oregon's purple loosestrife populations.