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Japanese knotweed (Polygonum cuspidatum) Links

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Contributors » Marcel Roy » Japanese knotweed (Polygonum cuspidatum)

Japanese knotweed (Polygonum cuspidatum) discovered by Marcel Roy (#565)

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Sighting Info

Observed: June 6, 2011 @ 2:00 PM
Posted on: June 7, 2011 @ 4:35 PM (diff: 1 days)
Japanese knotweed (Polygonum cuspidatum) is a perennial species with spreading rhizomes and numerous reddish-brown, freely branched stems. The plant can reach four to eight feet in height and is often shrubby. The petioled leaves are four to six inches long and generally ovate with an abrupt point. The whitish flowers are borne in open, drooping panicles. Japanese knotweed is a very aggressive species that is capable of crowding out all other vegetation. As its name indicates, Japanese knotweed is a native of Japan (Hickman 1993). However, it has become naturalized in North America, where it is found from Newfoundland and many parts of the northeastern U.S. An escaped ornamental, Japanese knotweed is often found in waste places, neglected gardens, roadsides, and along streambanks.

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Newfoundland Nature

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