Pictorial guide to the flora of the British Isles

Home ⟩ Pictorial Guide ⟩ Polygonaceae ⟩ Reynoutria japonica / Japanese knotweed

Reynoutria japonica Houtt.

Japanese knotweed (Polygonaceae)

 SpreadBias within British IslesDirection of bias
Very widespreadNegligible tendencyS
Plant Atlas 2020
BSBI Distribution Map

Synonyms | Fallopia japonica (Houtt.) Ronse Decr. | Polygonum cuspidatum Sieb. & Zucc.

Reynoutria japonica has powerful stems and leaves that are truncate at the base and hairless below.

Oxford (VC23: Oxfordshire); 2015-04-20

 Japanese knotweed / Reynoutria japonica: _Reynoutria japonica_ has powerful stems and leaves that are truncate at the base and hairless below.

Reynoutria japonica was once cultivated for its attractive flowers, but is now a proscribed weed in Great Britain under Schedule 9 of the Wildlife and Countryside Act 1981.

Manchester (VC59: South Lancashire); 2007-08-24

 Japanese knotweed / Reynoutria japonica: _Reynoutria japonica_ was once cultivated for its attractive flowers, but is now a proscribed weed in Great Britain under <a href="sched9.html">Schedule 9</a> of the Wildlife and Countryside Act 1981.

All images copyright © Christopher J. Dixon unless otherwise indicated.

L-R: Bidens tripartita, Melilotus officinalis, Mimulus guttatus, Thalictrum flavum, Ranunculus peltatus, Anchusa arvensis, Malva alcea, Lolium perenne