Polygonaceae
Japanese knotweed
Reynoutria japonica
- Family
- Polygonaceae
- Genus
- Reynoutria
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Common names
By language (35)
- Basque
- Japoniar piper-belar
- Bulgarian
- Японска фалопия
- Cantonese
- 虎杖
- Chinese
- 虎杖, 黃藥子, 大接骨, 斑庄根, 虎杖叶, 贯脚, 酸桶芦, 酸筒杆
- Croatian
- Japanski dvornik
- Czech
- Křídlatka japonská
- Danish
- Japanpileurt, Japan-Pileurt, Japansk Pileurt
- Dutch
- Japanse duizendknoop, Japanski dvornik
- English
- Japanese knotweed, Flowering bamboo, Japanese bindweed
- Esperanto
- Japana falopio
- Estonian
- Vooljas pargitatar
- Finnish
- Japanintatar, Sieboldintatar
- French
- Renouée du Japon, Renouee du Japon, Renouée bambou, Renouée japonaise
- German
- Japanischer Staudenknöterich, Japanischer Flügelknöterich, Spiessknöterich
- Hebrew
- ארכובית יפנית
- Hungarian
- Ártéri japánkeserűfű
- Icelandic
- Blómsúra
- Irish
- Glúineach bhiorach
- Japanese
- イタドリ, 虎杖, こじょう, ジャパニーズ・ノットウィード, スカンポ, フラワリング・バンブー, レイノウトリア・ジャポニカ, 酸模
- Korean
- 호장근
- Latvian
- Japānas dižsūrene
- Lithuanian
- Japoninis pelėvirkštis, Japoninė reinutrė
- lzh
- 虎杖
- Norwegian Bokmål
- Parkslirekne
- Persian
- فالوپیا جاپنیکا
- Polish
- Rdestowiec ostrokończysty
- Portuguese
- Sanguinária do Japão
- Russian
- Рейнутрия японская
- Slovak
- Pohánkovec japonský
- Slovenian
- Japonski dresnik
- Swedish
- Parkslide, Rosenslide
- szy
- Nipaluma-hucang, hocang
- Vietnamese
- Cốt khí củ, Cốt khí
- Welsh
- Canclwm Japan, Llysiau`r cythraul
- za
- Godiengangh
Synonyms
- Fallopia compacta (Hook.f.) G.H.Loos & P.Keil
- Fallopia japonica (Houtt.) Ronse Decr.
- Fallopia japonica f. colorans (Makino) Yonek.
- Fallopia japonica var. compacta (Hook.f.) J.P.Bailey
- Fallopia japonica var. compacta J.Bailey
- Fallopia japonica var. hachidyoensis (Makino) Yonek. & H.Ohashi
- Fallopia japonica var. uzenensis (Honda) Yonek. & H.Ohashi
- Pleuropterus cuspidatus (Siebold & Zucc.) H.Gross
- Pleuropterus zuccarinii Small
- Polygonum compactum Hook.f.
- Polygonum cuspidatum Siebold & Zucc.
- Polygonum cuspidatum var. spectabile Noter
- Polygonum hachidyoense Makino
- Polygonum reynoutria Makino
- Polygonum reynoutria f. colorans Makino
- Polygonum sieboldii de Vriese ex L.H.Bailey
- Polygonum zuccarinii Small
- Reynoutria compacta (Hook.f.) P.D.Sell
- Reynoutria hachidyoensis (Makino) Nakai
- Reynoutria hachidyoensis var. terminalis Honda
- Reynoutria hachijoensis Nakai ex Jotani
- Reynoutria hastata Nakai ex Ui
- Reynoutria henryi Nakai
- Reynoutria japonica var. compacta (Hook.f.) Buchheim
- Reynoutria japonica var. hastata (Nakai ex Ui) Honda
- Reynoutria japonica var. spectabilis (Noter) Moldenke
- Reynoutria japonica var. terminalis (Honda) Kitag.
- Reynoutria japonica var. uzenensis Honda
- Reynoutria uzenensis (Honda) Honda
- Tiniaria japonica (Houtt.) Hedberg
Flowers
- In flower
- August to September (from 2,202 flowering iNaturalist observations worldwide)
Photos
FlowerPhoto: Patrick Hacker, CC BY 4.0, from iNaturalist 
FlowerPhoto: dugald, CC0, from iNaturalist 
FlowerPhoto: Karim Haddad, CC BY 4.0, from iNaturalist 
FlowerPhoto: Ken Clark, CC BY 4.0, from iNaturalist 
FruitPhoto: Tyler Ekholm, CC BY 4.0, from iNaturalist 
Photo: W.carter, CC0, from Wikimedia Commons 
Photo: KENPEI, CC BY-SA 3.0, from Wikimedia Commons 
Photo: naturalist charlie, CC BY 4.0, from iNaturalist 
Photo: KENPEI, CC BY-SA 3.0, from Wikimedia Commons 
Photo: funnieanimals, CC0, from iNaturalist 
Photo: Koichi Oda, CC BY-SA 2.0, from Wikimedia Commons 
Photo: Daniel Cahen, CC BY 4.0, from iNaturalist
More in Reynoutria
Sources: classification, synonyms from World Flora Online Plant List (2026-06, CC0 1.0); common names, popularity from Wikidata (2026-10-26, CC0 1.0). About our plant data.