from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Any of various low-growing or shrubby plants of the family Polyganaceae, having jointed stems and small flowers.

from The Century Dictionary.

  • noun A plant of one of the species of knapweed or knobweed, Centaurea nigra, C. Cyanus, and C. Scabiosa: so called from the knot-like heads.
  • noun A plant of the genus Polygonum, which includes the doorweed, the smartweeds and water-pepper, the prince's-feather, etc.; knotgrass or jointweed: so called from the knotty stem.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Bot.) See knotgrass.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun Any of several plants of the genus Polygonum, with jointed stems and inconspicuous flowers


from Wiktionary, Creative Commons Attribution/Share-Alike License

knot +‎ weed


  • Resveratrol comes from grapes (hence the benefit of red wine), peanuts, berries, and a Chinese herb called hu zhang (polygonum cuspidate, also known as giant knotweed, which is a common ingredient in many Chinese herbal formulas).

    The UltraMind Solution

  • Some of the "pests" he offers include, Asian shore crabs and Japanese knotweed, which is listed as one of the world's 100 most invasive species. News

  • Japanese knotweed, which is native to Japan, Taiwan and China, was introduced by botanists into Britain in the 19th century as an ornamental plant.

    Environment news, comment and analysis from the Guardian |

  • Food supplement products containing natural versions of resveratrol such as those sourced from red wine, mulberries, peanuts and 'knotweed' (polygonum cuspidatum), will require Traditional Herbal Medicinal Product Directive

    NutraIngredients-USA RSS

  • Meadows consist mainly of Kobresia (K. pygmaea and K. humilis) and Carex atrata sedge, often associated with forbs such as knotweed (Polygonum sphaerostachyum), meadow rue (Thalictrum alpinum), everlasting (Anaphalis xylorrhiza), edelweiss (Leontopodium pusillum), blue poppy (Meconopsis horridula), Potentilla spp.,

    Tibetan Plateau alpine shrub and meadows

  • Could a tiny insect halt the invasion of Japanese knotweed?

    Country diary: Yeo Valley, Somerset

  • Some, such as the notorious Japanese knotweed, do immense harm.

    Invasive species: Killer shrimps and English parrots | Editorial

  • Jillie leads me through an opening in the brush, a path lined with white knotweed and purple morning glories that opens up, just beyond the briers of blackberry vines that have long been picked clean by quail and finches, into a meadow lighted with goldenrod and sunlight against the rusty tops of tall grasses, striving against the subtle blues of the lobelia and the aggressive reds of jack-in-the-pulpits.


  • Alien v predator: insect out to kill Japanese knotweed

    Country diary: Yeo Valley, Somerset

  • Predator to attack knotweed: '£150m damage every year'

    Country diary: Yeo Valley, Somerset


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