Japanese Knotweed (Fallopia japonica)
Indigenous to Japan, this perennial was introduced to North America in the 19th century. Japanese knotweed forms dense stands spreading predominantly by extensive rhizomes creating a very persistent and hard-to-kill plant. Small pieces of rhizome can produce new plants very quickly. The species can be found in riparian areas, wetlands, roadsides, utility right of ways and fence lines. This invasive species can grow up to a meter in height in three weeks. There are similar species, including Himalayan, Giant and Bohemian knotweeds. Japanese knotweed is considered to be one of the world’s most invasive plant species.