knotgrass

 
Pronunciation: /ˈnɒtgrɑːs/

noun

[mass noun]
  • a common Eurasian plant of the dock family, with jointed creeping stems and small pink flowers. It is a serious weed in some areas.
    • Genus Polygonum, family Polygonaceae: several species, in particular P. aviculare
  • any of a number of other plants, especially grasses, with jointed stems.