Connecticut Plants
Japanese Knotweed
Fallopia japonica (Houtt.) R. Decr.

Japanese knotweed is an invasive weed that threatens native plant habitats. More on this topic from Invasive Plant Atlas of New England.

  • Synonyms: Polygonum cuspidatum Sieb. & Zucc., Reynoutria japonica Houtt.
  • Family: buckwheat (Polygonaceae)
  • Habitat: roadsides, waste places, streambanks
  • Height: 4 to 10 feet
  • Flower size: 1/8 inch across
  • Flower color: yellowish- or greenish-white
  • Flowering time: July to October
  • Origin: Asia
Polygonum cuspidatum Sieb. & Zucc.
Polygonum cuspidatum Sieb. & Zucc.