Japanese Knotweed - Reynoutria japonica

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Alternative names
Fallopia japonica
Description

Vigorous, spreading, tall plant with stout erect stems to 2 metres. Stems can be bluish-green or reddish in colour, branched above. Leaves broadly oval, triangular, stalked. Flowers white, in narrow leafy panicles from upper leaf joints.

Identification difficulty
Habitat

Moist habitats, grassy banks, waste ground, roadside verges etc.

When to see it

August to October.

Life History

Perennial.

UK Status

Fairly frequent now over much of Britain except the far north.

VC55 Status

Fairly frequent (often invasive) in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 122 of the 617 tetrads.

  • David Gould
    nr. Braunstone Lane East
    01 September 2014
  • Graham Calow
    Sapcote
    06 September 2006
  • David Perrins
    Battram
    19 July 2011
  • Graham Calow
    Sapcote
    06 September 2006
  • David Nicholls
    Watermead Country Park
    27 September 2013
  • HAPeacock
    Swannington Line
    24 May 2012

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Species data profile ?

Species profile

Common names
Japanese Knotweed
Species group:
flowering plant
Kingdom:
Plantae
Order:
Caryophyllales
Family:
Polygonaceae
Records on NatureSpot:
72
First record:
06/09/2006 (Calow, Graham)
Last record:
28/08/2025 (Pochin, Christine)

Total records by month

% of records within its species group

10km squares with records

The latest images and records displayed below include those awaiting verification checks so we cannot guarantee that every identification is correct. Once accepted, the record displays a green tick.

In the Latest Records section, click on the header to sort A-Z, and again to sort Z-A. Use the header boxes to filter the list.

Latest images

Latest records

  • Graham Calow
    A5 near High Cross
    03 June 2016
  • Graham Calow
    A5 near High Cross
    03 June 2016
  • Graham Calow
    A5 near High Cross
    07 June 2016
  • Graham Calow
    Near High Cross
    01 June 2016
  • Graham Calow
    Wykin
    12 May 2015
  • Graham Calow
    Wykin
    12 May 2015
  • Graham Calow
    Sapcote
    29 August 2007
  • David Nicholls
    Watermead Country Park
    27 September 2013
  • HAPeacock
    Swannington Line
    24 May 2012
  • Graham Calow
    Ellistown
    27 June 2011
  • Alan Semper
    Harby garden
    11 September 2009
  • Graham Calow
    Ellistown
    27 June 2011
  • David Perrins
    Battram
    19 July 2011
  • HAPeacock
    Swannington Line
    24 May 2012
  • Alan Semper
    Harby, pub car park
    22 August 2012
  • Alan Semper
    Harby, pub car park
    22 August 2012
  • Graham Calow
    Stanton Lakes
    13 June 2013
  • Graham Calow
    A5 Witherley
    06 August 2015
  • AJ Cann
    Welford Road Cemetery
    10 July 2015
  • Graham Calow
    A5 near High Cross
    03 June 2016
  • Graham Calow
    Battram Road, Battram
    12 May 2016
  • Graham Calow
    A5 near High Cross
    03 June 2016
  • Graham Calow
    Battram
    24 May 2016
  • Graham Calow
    Battram Road, Battram
    12 May 2016