Purple loosestrife

Purple loosestrife (Lythrum salicaria) is a flowering plant belonging to the family Lythraceae. This herbaceous perennial plant is native to temperate regions of Europe, Asia, northern Africa, and eastern Australia.

Purple loosestrife has been introduced into temperate North America where it is now widely naturalized (spreading on its own). Infestations may rarely result in dramatic disruption in water flow in rivers and canals, and the life cycles of organisms from waterfowl to amphibians to algae being affected.

Main Photo Credit: 
"Purple loosestrife (Lythrum salicaria), Finland" by Veljmies, 2014. CC BY-NC 2.0.

Description: Wikipedia