Japanese knotweed

Japanese knotweed, or Polygonum cuspidatum is an invasive plant in the Polygonaceae family that is widely regarded as a weed. Other common names for it include fleeceflower, huzhang, Hancock's curse, Japanese bamboo, and Mexican bamboo. Other scientific names for it include Fallopia japonica and Reynoutria japonica. This plant is a large, herbaceous perennial with hollow, noded stems that give it the appearance of bamboo, though it is not related. A colonizer of riparian ecosystems, roadsides and waste places, it can be found in 40 out 50 of the U.S. states, and 6 Canadian provinces. It is a frequent invader in Europe and the U.K., where it has been illegal to spread Japanese knotweed in England since the 1980s. Native to Asia, Japanese knotweed was first introduced to Europe and the US in the 19th century.

Closely related species include "Giant knotweed" (Polygonum sachalinense) and "Russian vine" (Polygonum aubertii).

External links:

• http://www.invasivespecies.gov/profiles/japktwd.shtml
• http://www.ecy.wa.gov/programs/wq/plants/weeds/aqua015
• http://fisher.bio.umb.edu/knotweed