Giant Knotweed, Fallopia sachalinensis


Short description of Fallopia sachalinensis, Giant Knotweed

It is a giant, erect perennial herb which forms dense thickets. Stems grow 4-5 m in a single season and bear large, alternate leaves up to 40cm long with heart-shaped bases. In summer plants bear dense panicles of small green-white flowers and seed is sometimes produced. It hybridises with Japanese Knotweed to give a highly invasive hybrid knotweed F. x bohemica.

Description of Fallopia sachalinensis, Giant Knotweed status in GB

Giant knotweed has been planted in large gardens and private estates for at least 100 years and has escaped into the wild via throw-outs and river flooding. It is widespread but not abundant across the British Isles and is much less common than Japanese Knotweed.

Habitat summary: Fallopia sachalinensis, Giant Knotweed

Its most characteristic habitat in GB is on riverbanks. It also occurs on lake shores, around Scottish sea lochs and in various lowland disturbed habitats.

Overview table

Environment: Terrestrial
Species status: Non-Native
Native range: Russian Far East, Eastern Asia, Kazan-retto, Nansei-shoto, Ogasawara-shoto, Sakhalin
Functional type: Land plant
Status in England: Non-Native
Status in Scotland: Non-Native
Status in Wales: Non-Native
Location of first record: v.c.H39
Date of first record: 1896

Distribution map

GB Distribution from BSBI

Author's name:

Sharon Pilkington

Last updated:

August 8th, 2011

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