The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Lycopus europaeus
Lycopus europaeus
(European bugleweed)

Copyright Info
Lycopus europaeus L.

Common name: European bugleweed

Synonyms and Other Names: Lycopus europaeus ssp. mollis (Kern.) Rothm. ex. Skalický, Lycopus europaeus var. mollis (Kern.) Briq., European bugleweed, marsh horehound, gipsywort, gypsywort

Taxonomy: available through www.itis.govITIS logo

Identification: Hairy perennial herb with two-lipped flowers. Flowers small, white, tubular, with free petal lobes of no particular unique structure. Calyx with a series of spiny projections giving the flower clusters a bristly appearance. Flowers clustered in the leaf axils. Stem naked or finely downy. Leaves elongate, narrow, deeply cut with toothlike lobes. Rhizomes transverse, producing long stolons enlarged at apex,

Size: to 1.2 m in height.

Native Range: Eurasia and Asia

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Lycopus europaeus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AL200820081South Atlantic-Gulf Region
CT201120111Outlet Connecticut River
IL199520116Des Plaines; Lower Fox; Upper Fox; Upper Illinois; Upper Illinois; Upper Mississippi Region
IN200820081Ohio Region
ME200820081New England Region
MD200820081Mid Atlantic Region
MA200820081New England Region
MI196820087Great Lakes Region; Huron; Lake Huron; Ottawa-Stony; Pigeon-Wiscoggin; Raisin; Western Lake Erie
NJ200820081Mid-Atlantic Region
NY187920086Great Lakes Region; Headwaters St. Lawrence River; Long Island; Lower Genesee; Lower Hudson; Middle Hudson
OH197020083Lake Erie; Southern Lake Erie; Western Lake Erie
PA200820082Lower Delaware; Lower Susquehanna
VA186018601Hampton Roads
WA200820081Pacific Northwest Region
WI198920222Milwaukee; Upper Fox

Table last updated 6/12/2024

† Populations may not be currently present.

* HUCs are not listed for states where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).

Ecology: Lycopus europaeus is a perennial forb that prefers to grow in wet soils and can tolerate flooding. It can be found in fens, fen cars, dune-slacks, ditches, and shorelines (Online Atlas 2012). It can grow in a variety of soils: sandy, loamy, or clay, and acidic, neutral, or basic. European water horehound can grow in full sun to semi-shade (light woodland).

Lycopus europaeus flowers from June to September. The flowers have both male and female organs and are pollinated by bees and flies (OWC NERR 2011, Percival 1947). The seeds ripen and disperse from August to October (OWC NERR 2011).

Lycopus europaeus seeds are very buoyant and be transported via waterways (Vogt et al. 2006). Ninety percent of seeds were still float after 176 days in stagnant water or 256 days in moving water (van den Broek et al. 2005). Seeds can also withstand passing through the digestive track of several species. Cosyns et al. (2005) found that a portion of seeds were viable after being eaten by horses and cattle. Lycopus europaeus seeds that passed through the digestive track of mallard ducks had a high germination rate (>25%). It is probable that mallard ducks are responsible, at least in part, for the long-range dispersal of European water horehound (Soons et al. 2008).

In order for germination to occur, the temperature needs to be above 12°C and below 33°C (Brändel 2006). Brändel (2005) also found that seeds exposed to fluctuating temperatures had higher germination rates.

The root system of L. europaeus contains rhizomes (Online Atlas 2012).

Means of Introduction: Solid ballast

Status: Established

Impact of Introduction: Invades wetlands, displaces native Lycopus sp.  It is also reputed to have medicinal qualities and has been used by various peoples as an astringent, cosmetic, douche, narcotic and refrigerant. It has also been used to treat fever, hypothyreosis, sores and wounds.

References: (click for full references)

Beer, A.M., K.R. Wiebelitz, and K. Schmidt-Gayk. 2008. Lycopus europaeus (gypsywort): effects on the thyroidal parameters and symptoms associate with thyroid function. Phytomedicine 15(1—2): 16—22.

Boedeltje, G., J.P. Bakker, R.M. Bekker, J.M. van Groenendael, and M. Soesbergen. 2003. Plant dispersal in a lowland stream in relation to occurrence and three specific life-history traits of the species in the species pool. Journal of Ecology 91: 855—866.

Brändel, M. 2006. Effect of temperatures on dormancy and germination in three species in the Lamiaceae occurring in northern wetlands. Wetlands Ecology and Management 14: 11—28.

Cosyns, E., S. Claerbout, I. Lamoot, and M. Hoffmann. 2005. Endozoochorous seed dispersal by cattle and horse in a spatially heterogeneous landscape. Plant Ecology 178(2): 149 — 162.

Fecka, I., and W. Cisowski. 1999. Multiple gradient development TLC in analysis of complex phenolic acids from Lycopus europaeus L. Chromatographia 49(5/6): 256—260.

Francis, R.A., and S.P.G. Hoggart. 2011. The flora of urban river wallscapes. River Research and Applications: 1—17.

Gibbons, S., M. Oluwatuyi, N.C. Veitch, and A.L. Gray. 2003. Bacterial resistance modifying agents from Lycopus europaeus. Phytochemistry 62(1): 83—87.

Hussein, A.A., B. Rodríguez, M. de la Paz Martínez-Alcázar, and F.H. Cano. 1999. Diterpenoids from Lycopus europaeus and Nepeta septemcrenata: Revised structures and new isopimarane derivatives. Tetrahedron 55(23): 7375—7388.

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.  

López, V., S. Akerreta, E. Casanova, J.M. García-Mina, R.Y. Cavero, and M.I. Calvo. 2007. In vitro antioxidant and anti-rhizopus activities of Lamiaceae herbal extracts. Plant Foods for Human Nutrition 62: 151—155.

Lucassen, E.C.H.E.T., A.J.P. Smolders, G. Boedeltje, P.J.J. van den Munckhof, and J.G.M. Roelofs. 2006. Groundwater input affecting plant distribution by controlling ammonium and iron availability. Journal of Vegetation Science 17: 425—434.

NatureServe. 2008. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. Accessed 24 July 2008.

Old Woman Creek National Estuarine Research Reserve (OWC NERR). 2011. Old Woman Creek National Estuarine Research Reserve Management Plant 2011—2016. Advisory Council of the Old Woman Creek National Estuarine Research Reserve. 504 pp. Available http://www.dnr.state.oh.us/LinkClick.aspx?fileticket=F1xA4WUmG8k%3D&tabid=15312

Online Atlas of the British & Irish Flora. 2012. Lycopus europaeus (Gipsywort). Botanical Society of the British Isles, Biological Records Centre, Joint Nature Conservation Committee, Centre for Ecology & Hydrology. Available http://www.brc.ac.uk/plantatlas/index.php?q=plant/lycopus-europaeus. Accessed 14 September 2012.

Percival, M. 1947. Pollen collection by Aphis mellifera. New Phytologist 46(1): 142—165.

Plant For A Future. 2008. http://www.pfaf.org/index.php 

Radulovic, N., M. Denic, and Z. Stojanovic-Radic. 2010. Antimicrobial phenolic abietane diterpene from Lycopus europaeus L. (Lamiaceae). Bioorganic & Medicinal Chemistry Letters 20(17): 4988—4991.

Reznicek, A.A., E.G. Voss, and B.S. Walters. 2011. Michigan Flora Online. University of Michigan. Available http://michiganflora.net/. Accessed 6 Septemeber 2012.

Soons, M.B., C. van der Vlugt, B. van Lith, G.W. Heil, and M. Klaassen. 2008. Small seed size increase the potential for dispersal of wetland plants by ducks. Journal of Ecology 96: 619—627.

Stammel, B., K. Kiehl, and J. Pfadenhauer. 2003. Alternative management on fens: Response of vegetation to grazing and mowing. Applied Vegetation Science 6:245—254. 

United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS). 2012. PLANTS Database. Threatened & Endangered. Available http://plants.usda.gov/threat.html. Accessed 23 July 2012.

U.S. Environmental Protection Agency (USEPA). 2008. Predicting future introductions of nonindigenous species to the Great Lakes. Washington DC. 138 pp.

van den Broek, T., R. van Diggelen, and R. Bobbink. 2005. Variation in seed buoyancy of species in wetland ecosystems with different flooding dynamic. Journal of Vegetation Science 16: 579—586.

van der Valk, A.G. and J.T.A. Verhoeven. 1988. Potential role of seed banks and understory species in restoring quaking fens from floating forests. Vegetatio 76(1/2): 3—13.

Vogt, K., L. Rasran, and K. Jensen. 2006. Seed deposition in drift lines during an extreme flooding event- Evidence for hydrochorous dispersal? Basic and Applied Ecology 7(5): 422—432.

Vonhoff, C., A. Baumgertner, M. Hegger, B. Korte, A. Biller, and H. Winterhoff. 2006. Extract of Lycopus europaeus L. reduces cardiac signs of hyperthyroidism in rats. Life Sciences 78(10): 1063—1070.

Wojciechowski, H., H.G. Gumbinger, U. Vahlensieck, H. Winterhoff, A. Nahrstedt, and F.H. Kemper. 2003. Analysis of the components of Lycopus europaeus L. in body fluids during metabolism studies comparison of capillary electrophoresis and high-performance liquid chromatography. Phytochemistry 62(1): 83—87.

Zinck, M. and A.E. Roland. 1998. Roland's Flora of Nova Scotia; rev. M. Zinck; 2 Vol. 3rd edition.

Author: Cao, L., and L. Berent.

Revision Date: 9/23/2012

Citation Information:
Cao, L., and L. Berent., 2024, Lycopus europaeus L.: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=2694, Revision Date: 9/23/2012, Access Date: 6/12/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


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Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/12/2024].

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