Fallopia japonica (Houtt.) Ronse Decr.

English Japanese knotweed ISEIA: A3 – Black List
Lëtzebuergesch Japanescht Knuetkraut EASIN
Français Renouée du Japon, renouée bambou Wikipedia: Wikipedia - English - Japanese knotweed Wikipedia - Français - Renouée du Japon Wikipedia - Deutsch - Japanischer Staudenknöterich Wikipedia - Nederlands - Japanse duizendknoop  Wikipedia - Português - Fallopia
Deutsch Japanischer Staudenknöterich, J. Flügelknöterich Wikispecies: Wikispecies - Japanese knotweed
Nederlands Japanse duizendknoop Back to the list of neophytes

Report the species

Report Fallopia japonica to the National Museum of Natural History.

Importance and distribution in Luxembourg

Distribution map of Fallopia japonica (Houtt.) Ronse Decr. in Luxembourg. Recorder database, MNHNL, 19.01.2019.

The first documented occurrence of the species in Luxembourg dates from 1952. It was found by Marcel Etringer on 2nd June 1952 between Rumelange and Tétange, municipality of Rumelange (Herbier specimen). There are 1.050 observations indicated in the Recorder database (18/01/2018).

Japanese knotweed is one of the most common and widespread invasive neophytes in Luxembourg. It builds huge colonies along riparian ecosystems, several major rivers of Luxembourg being affected. A worst case example can be seen along the river Sure between Ettelbruck and Michelau.

It is regularly found building smaller colonies along roadsides and in waste grounds, most of these places have been “contaminated” by people getting rid of knotweed clippings from their gardens. This can easily be seen along the main road leaving Luxembourg-City in the direction of Echternach.

Nurseries and garden designers sometimes contribute to the spread of Japanese knotweed in gardens and public green spaces by using contaminated compost.

Japanese knotweed is much more widespread in Luxembourg than its taller “cousin”, the Sakhalin knotweed (Fallopia sachalinensis).

As part of a study for the Department of Ecology section of the National Museum of Natural History, samples of 31 specimens of Fallopia species have been collected in 2017. The sampled specimens were described and leaves and stem parts were collected for integration in the museums herbarium. The samples have been subjected to genetic analysis by the museum’s lab. The results show that F. x bohemica is much more common than Fallopia japonica. The distruibution data of both species need to be updated.

Japanese knotweed in a public green space at the entrance of the regional school in the municipality of Tandel. © 27.06.2006 by Christian Ries.

Risk assessment

ISEIA protocol: A3 (3+3+3+3) = Black List (Ries et al. 2013: 18). Needs to be reassessed (see above).

Bibliography concerning Luxembourg

  • Albers, M., S. Kohn, J. Steng & M. Pfeiffenschneider, 2001. – Problematik der Bioinvasion. Kartierung von Japan-Knöterich, Riesenbärenklau und Indischem Springkraut an Woltz, Clerve und Wiltz. Ergebnisse der Kartierung. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, arrondissement nord. August 2001. 7S. + Anhang.
  • Glesener, B., M. Pfeiffenschneider & C. Ries, 2009. Die Verbreitung von Impatiens glandulifera, Fallopia japonica, F. sachalinensis, F. ×bohemica und Heracleum mantegazzianum entlang der Hauptfließgewässer Luxemburgs. Bull. Soc. Nat. luxemb. 110 : 69-73. (pdf)
  • Pfeiffenschneider, M., 2001. – Problematik der Bioinvasion. Nationales Inventar von Riesenbärenklau, Indischem Springkraut und exotischen Knötericharten. Ergebnisse einer Umfrage und Konzept zur Bekämpfung der Riesenbärenklaubestände. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, Service de la conservation de la nature, November 2001. 23 S. + Anhang, Luxembourg.
  • Pfeiffenschneider, M., 2007. Über die Verbreitung von Heracleum mantegazzianum, Impatiens glandulifera, Fallopia japonica und F. sachali­nensis entlang der Gewässer Obersauer, Woltz, Clerve, Wiltz und ihrer Nebengewässer (Luxemburg). Bull. Soc. Nat. luxemb. 108 : 7-10. (pdf)
  • Pfeiffenschneider, M., 2008. Neophyten in Luxemburg – Projekt Bioinvasion 2007. Arbeitsbericht. 18 S. (pdf)
  • Pfeiffenschneider, M. & M. Owaller, 2000. – Kartierung von Japan-Knöterich, Riesenbärenklau und Indischem Springkraut an der Obersauer. Theoretische Grundlagen und Ergebnisse der Kartierung. – Studie des Büros ERSA im Auftrag von: Administration des eaux & forêts, acrrondissement nord. August 2000. 37S. + Anhang, Luxembourg.
  • Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]

Suggested citation of this webpage

Ries, C. & M. Pfeiffenschneider (Eds.), 2019. Fallopia japonica (Houtt.) Ronse Decr. In: neobiota.lu - Invasive Alien Species in Luxembourg. URL: https://neobiota.lu/fallopia-japonica/ [19.01.2019].

 Last updated on Tue, Aug 7, 2018.