Flora of Northern Ireland
  • Fallopia sachalinensis (F.Schmidt ex Maxim.) Ronse Decraene - Giant Knotweed - Polygonaceae
Fallopia sachalinensis
© Paul Hackney
Fallopia sachalinensis
© Paul Hackney
Fallopia sachalinensis
© Paul Hackney
Fallopia sachalinensis
(Map updated: March 2008)
Fallopia sachalinensis
© Paul Hackney
 

This is a vigorous perennial knotweed, forming huge clumps up to 10 feet high. It is similar to Japanese knotweed (Fallopia japonica), but rarer. Both male and female plants occur in Northern Ireland (unlike F. japonica which only produces female flowers in Ireland) and its pollen can fertilize F. japonica flowers to produce a rare hybrid when the two species grow near together.

A native of Korea, Japan and Sakhalin, introduced to Europe for gardens. It is found on riversides and waste ground, the products of discarded garden waste containing fragments of the plant.

All names: Fallopia sachalinensis (F.Schmidt ex Maxim.) Ronse Decraene; Reynoutria sachalinensis (F.Schmidt ex Maxim.) Nakai; Polygonum sachalinensis F.Schmidt ex Maxim.; Polygonum sachalinense F.Schmidt.