Giant Knotweed
Reynoutria sachalinensis (F.Schmidt) Nakai
- light
- —
- water
- —
- tall
- 3.0 m
- wide
- —
Polygonaceae
Also called Sakhalin Knotweed, Sacaline
Formerly Fallopia sachalinensis, Pleuropterus sachalinensis, Polygonum sachalinense, Reynoutria brachyphylla, and 1 more
When it flowers
Not known yet in the tropics: too few flowering observations to read a season from.
Read from iNaturalist photographs of it in flower. A month counts at 50% of the best month's flowering share (smoothed over three months) and 10% of its flowering count, from at least 100 flowering observations in the band.
If a child, a pet or anyone may have eaten a plant, contact a doctor or vet straight away, or call the National Poisons Information Centre (AIIMS, New Delhi) on 1800 116 117, free and open 24 hours.
Something wrong with it?About it
- Grows as
- PerennialKew's checklist, not yet checked
- Climate
- TemperateKew's checklist, not yet checked
- Wild in
- S. Sakhalin to N. & C. Japan, Korea (Ulleungdo)Kew's checklist, not yet checked
- Height
- 2.0 m to 4.0 mRead from Wikipedia, one source
Not known yet: light, spread, water, flowers, coldest it survives, heat, hottest it survives.
In other languages (12)
- Czech
- křídlatka sachalinská
- Norwegian Bokmål
- kjempeslirekne
- Dutch
- Sachalinse Duizendknoop
- root
- FALSAC
- Japanese
- オオイタドリ
- French
- Renouée de Sakhaline
- Danish
- Kæmpe-pileurt
- Russian
- Рейнутрия сахалинская, Гречишка сахалинская, Горец сахалинский
- German
- Sachalin-Staudenknöterich, Russischer Staudenknöterich, Sachalin-Knöterich
- Finnish
- sahalinintatar
- Lithuanian
- Sachalininė reinutrė, Sachalininis pelėvirkštis
- Polish
- Rdestowiec sachaliński
Where this comes from
- iNaturalist, read 2026-10-25, CC0-1.0 (observation counts)
- Wikidata, read 2026-10-25, CC0-1.0
- Kew's checklist, read 2026-10-24, CC-BY-4.0
- Wikipedia, read 2026-10-26, fact, cited
- Wikimedia Commons, read 2026-10-25, Public domain
- iNaturalist, read 2026-10-25, CC0
- iNaturalist, read 2026-10-25, CC0
- iNaturalist, read 2026-10-25, CC BY
- 3D model: Reynoutria sachalinensis (built for Vanagrha) by Vanagrha, own
A fact “checked by a majority of its sources” was settled by a vote of the pages it was read from, not by a person reading it; one marked “one source” rests on that page alone. Anything else not marked checked has not been checked yet. Where nothing is known, the page says so rather than guess.