Lagarosiphon major Ridl. Moss ex Wager

English Curly waterweed ISEIA: A0 – Alert List. IAS of EU concern.
Lëtzebuergesch Gekréngelt Waasserpescht EASIN
Français Elodée crépue Wikipedia: Wikipedia - English - Curly waterweed
Deutsch Wechselblatt-Wasserpest Wikispecies: Wikispecies - Lagarosiphon major
Nederlands Verspreidbladige waterpest Back to the list of neophytes

Report the species

Report Lagarosiphon major to the National Museum of Natural History.

Importance and distribution in Luxembourg

Distribution map of Lagarosiphon major Ridl. Moss ex Wager in Luxembourg. Recorder-LUX & iNaturalist, 2019.08.21.

Lagarosiphon major, curly waterweed, preferably develops in clear, still or slow-flowing water systems. It can live in a wide range of trophic conditions providing that a silty or sandy bottom rich in nutrients is available. It prefers well-lit environments. The plant makes dense monospecific populations which often colonise whole water bodies, restrict water movement, cut off light, produce anoxic conditions and trap sediments in the system. The species has been reported to outcompete native aquatic plants and to affect associated populations of aquatic invertebrates and vertebrates. Dense beds provide a poor habitat for aquatic animals and are not consumed by fish. They interfere with recreational activities and increase the risk of adjacent land flooding (Source:

The species has not yet been observed in Luxembourg.

Risk assessment

ISEIA protocol: A0 (2+3+3+3) = Alert List (Ries et al. 2013: 18).

Bibliography concerning 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. Lagarosiphon major Ridl. Moss ex Wager. In: - Invasive Alien Species in Luxembourg. URL: [21.08.2019].

 Last updated on Friday, April 13, 2018.