any of several knotty-stemmed plants belonging to the genus Polygonum, of the buckwheat family.

Origin of knotweed

First recorded in 1570–80; knot1 + weed1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for knotweed

Contemporary Examples of knotweed

  • Japanese knotweed, for all its invasive attributes, was an ornamental plant for the Victorians.

    The Daily Beast logo
    The Best of Brit Lit

    Peter Stothard

    December 17, 2010

Historical Examples of knotweed

  • It is Polygonum Virginicum, and so far without a common name, unless Virginia knotweed be satisfactory.

    Seed Dispersal

    William J. Beal

  • Those of us who are gardeners will certainly agree that “unfortraedde” is the right name for knotweed.

    The Old English Herbals

    Eleanour Sinclair Rohde

British Dictionary definitions for knotweed



any of several polygonaceous plants of the genus Polygonum, having small flowers and jointed stems
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012