Biological Invasions

, Volume 12, Issue 7, pp 1967–1999 | Cite as

Should we care about purple loosestrife? The history of an invasive plant in North America

Original Paper


Purple loosestrife (Lythrum salicaria L., Lythraceae) is considered one of the worst invasive plant species in the world. In this paper, I reconstruct how purple loosestrife quickly became, after a long (150 years) period of indifference, the persona non grata of North American wetlands. I then compare the portrayal of the species in newspapers (907 articles) to that supported by the scientific literature (38 peer-review papers). The depiction of purple loosestrife in scientific studies (lacking definition) is far removed from that in newspapers (alarming). Some native species likely suffer from an invasion, but stating that this plant has large negative impacts on wetlands is probably exaggerated. If purple loosestrife is not a primary cause of extinction or a major contributor to the decline of other species, but is instead an indicator of anthropogenic disturbances, the resources and efforts devoted to removing this species might be better focused on more effective means to protect wetlands against disturbances.


Biological control Invasive plant species Lythrum salicaria Media Purple loosestrife Wetland 



This work was financially supported by the Natural Science and Engineering Research Council of Canada. I thank Jacques Brisson and Jacques Brodeur (Université de Montréal), Conrad Cloutier (Université Laval) and Sylvie de Blois (McGill University), all invasive plant or biological control specialists, Jean Hamann (Université Laval), science journalist, and two anonymous reviewers for heated debates and numerous comments on earlier drafts of this paper.


  1. Anderson MG (1995) Interactions between Lythrum salicaria and native organisms: a critical review. Environ Manage 19:225–231CrossRefGoogle Scholar
  2. Balogh GR, Bookhout TA (1989) Purple loosestrife in Ohio’s Lake Erie marshes. Ohio J Sci 89:62–64Google Scholar
  3. Barbier E, Knowler D (2006) Commercialization decisions and the economics of introduction. Euphytica 148:151–164CrossRefGoogle Scholar
  4. Bärlocher F, Biddiscombe NR (1996) Geratology and decomposition of Typha latifolia and Lythrum salicaria in a freshwater marsh. Arch Hydrobiol 136:309–325Google Scholar
  5. Benoit LK, Askins RA (1999) Impact of the spread of Phragmites on the distribution of birds in Connecticut tidal marshes. Wetlands 19:194–208CrossRefGoogle Scholar
  6. Blossey B (1999) Before, during and after: the need for long-term monitoring in invasive plant species management. Biol Invasions 1:301–311CrossRefGoogle Scholar
  7. Blossey B (2002) Purple loosestrife. In: Van Driesche R, Lyon S, Blossey B, Hoddle M, Reardon R (eds) Biological control of invasive plants in the eastern United States. United States Department of Agriculture, Forest Service, Publication no. FHTET-2002–2004, Washington (DC), pp 149–157Google Scholar
  8. Blossey B, Skinner LC, Taylor J (2001) Impact and management of purple loosestrife (Lythrum salicaria) in North America. Biodivers Conserv 10:1787–1807CrossRefGoogle Scholar
  9. Brown BJ, Mitchell RJ (2001) Competition for pollination: effects of pollen of an invasive plant on seed set of a native congener. Oecologia 129:43–49CrossRefGoogle Scholar
  10. Brown BJ, Mitchell RJ, Graham SA (2002) Competition for pollination between an invasive species (purple loosestrife) and a native congener. Ecology 83:2328–2336CrossRefGoogle Scholar
  11. Brown CJ, Blossey B, Maerz JC, Joule SJ (2006) Invasive plant and experimental venue affect tadpole performance. Biol Invasions 8:327–338CrossRefGoogle Scholar
  12. Carson WP, Hovick SM, Baumert AJ, Bunker DE, Pendergast TH IV (2008) Evaluating the post-release efficacy of invasive plant biocontrol by insects: a comprehensive approach. Arthropod-Plant Interactions 2:77–86CrossRefGoogle Scholar
  13. Catling PM, Mitrow G (2007) A prioritized list of the invasive alien plants of natural habitats in Canada. Can Bot Ass Bull 38:55–57Google Scholar
  14. Dech JP, Nosko P (2002) Population establishment, dispersal and impact of Galerucella pusilla and G. calmariensis, introduced to control purple loosestrife in central Ontario. Biol Control 23:228–236CrossRefGoogle Scholar
  15. Delisle F, Lavoie C, Jean M, Lachance D (2003) Reconstructing the spread of invasive plants: taking into account biases associated with herbarium specimens. J Biogeogr 30:1033–1042Google Scholar
  16. Denoth M, Myers JH (2005) Variable success of biological control of Lythrum salicaria in British Columbia. Biol Control 32:269–279CrossRefGoogle Scholar
  17. Denoth M, Myers JH (2007) Competition between Lythrum salicaria and a rare species: combining evidence from experiments and long-term monitoring. Plant Ecol 191:153–161CrossRefGoogle Scholar
  18. Diehl JK, Holliday NJ, Lindgren CJ, Roughley RE (1997) Insects associated with purple loosestrife, Lythrum salicaria L., in southern Manitoba. Can Entomol 129:937–948CrossRefGoogle Scholar
  19. Dow Jones & Company (2008) Dow Jones Factiva. Available via
  20. Doyon D (1953) Essais de rénovation de la végétation naturelle de la Commune de Baie du Febvre. Faculté d’agriculture de l’Université Laval, Sainte-Anne-de-la-PocatièreGoogle Scholar
  21. Emery SL, Perry JA (1996) Decomposition rates and phosphorus concentrations of purple loosestrife (Lythrum salicaria) and cattail (Typha spp.) in fourteen Minnesota wetlands. Hydrobiologia 323:129–138CrossRefGoogle Scholar
  22. Farnsworth EJ, Ellis DR (2001) Is purple loosestrife (Lythrum salicaria) an invasive threat to freshwater wetlands? Conflicting evidence from several ecological metrics. Wetlands 21:199–209CrossRefGoogle Scholar
  23. Fernald ML (1938) Must all rare plants suffer the fate of Franklinia? J Franklin Inst 226:383–397CrossRefGoogle Scholar
  24. Fickbohm SS, Zhu W-X (2006) Exotic purple loosestrife invasion of native cattail freshwater wetlands: effects on organic matter distribution and soil nitrogen cycling. Appl Soil Ecol 32:123–131CrossRefGoogle Scholar
  25. Gabor TS, Haagsma T, Murkin HR, Armson E (1995) Effects of triclopyr amine on purple loosestrife and non-target wetland plants in south-eastern Ontario, Canada. J Aquat Plant Manage 33:48–51Google Scholar
  26. Gabor TS, Haagsma T, Murkin HR (1996) Wetland plant responses to varying degrees of purple loosestrife removal in southeastern Ontario, Canada. Wetlands 16:95–98CrossRefGoogle Scholar
  27. Gardner SC, Grue CE, Major WW, Conquest LL (2001) Aquatic invertebrate communities associated with purple loosestrife (Lythrum salicaria), cattail (Typha latifolia), and bulrush (Scirpus acutus) in central Washington, USA. Wetlands 21:593–601CrossRefGoogle Scholar
  28. Gaudet CL, Keddy PA (1988) A comparative approach to predicting competitive ability from plant traits. Nature 334:242–243CrossRefGoogle Scholar
  29. Gaudet CL, Keddy PA (1995) Competitive performance and species distribution in shoreline plant communities: a comparative approach. Ecology 76:280–291CrossRefGoogle Scholar
  30. Grabas GP, Laverty TM (1999) The effect of purple loosestrife (Lythrum salicaria L.; Lythraceae) on the pollination and reproductive success of sympatric co-flowering wetland plants. Écoscience 6:230–242Google Scholar
  31. Grevstad FS (2006) Ten-year impacts of the biological control agents Galerucella pusilla and G. calmariensis (Coleoptera: Chrysomelidae) on purple loosestrife (Lythrum salicaria) in Central New York State. Biol Control 39:1–8CrossRefGoogle Scholar
  32. Grout JA, Levings CD, Richardson JS (1997) Decomposition rates of purple loosestrife (Lythrum salicaria) and Lyngbyei’s sedge (Carex lyngbyei) in the Fraser River estuary. Estuaries 20:96–102CrossRefGoogle Scholar
  33. Gurevitch J, Padilla DK (2004) Are invasive species a major cause of extinctions? Trends Ecol Evol 19:470–474CrossRefPubMedGoogle Scholar
  34. Hager HA (2004) Competitive effect versus competitive response of invasive and native wetland plant species. Oecologia 139:140–149CrossRefPubMedGoogle Scholar
  35. Hager HA, McCoy KD (1998) The implications of accepting untested hypotheses: a review of the effects of purple loosestrife (Lythrum salicaria) in North America. Biodivers Conserv 7:1069–1079CrossRefGoogle Scholar
  36. Hager HA, Vinebrooke RD (2004) Positive relationships between invasive purple loosestrife (Lythrum salicaria) and plant species diversity and abundance in Minnesota wetlands. Can J Bot 82:763–773CrossRefGoogle Scholar
  37. Hanson SR, Osgood DT, Yozzo DJ (2002) Nekton use of a Phragmites australis marsh on the Hudson River, New York, USA. Wetlands 22:326–337CrossRefGoogle Scholar
  38. Hickey JM, Malecki RA (1997) Nest site selection of the Black Tern in western New York. Colonial Waterbirds 20:582–595CrossRefGoogle Scholar
  39. Houlahan JE, Findlay CS (2004) Effect of invasive plant species on temperate wetland plant diversity. Conserv Biol 18:1132–1138CrossRefGoogle Scholar
  40. House HD (1924) Annotated list of the ferns and flowering plants of New York State. New York State Museum Bull 254:1–759Google Scholar
  41. Invasive Species Specialist Group (2008) Global invasive species database. International union for conservation of nature. Available via
  42. Keddy PA, Twolan-Strutt L, Wisheu IC (1994) Competitive effect and response rankings in 20 wetland plants: are they consistent across three environments? J Ecol 82:635–643CrossRefGoogle Scholar
  43. Keller BEM (2000) Plant diversity in Lythrum, Phragmites, and Typha marshes, Massachusetts, USA. Wetlands Ecol Manage 8:391–401CrossRefGoogle Scholar
  44. Knowlton CH, Deane W (1921) Reports on the flora of the Boston District. XXXIV. Rhodora 23:113–118Google Scholar
  45. Landis DA, Sebolt DC, Haas MJ, Klepinger M (2003) Establishment and impact of Galerucella calmariensis L. (Coleoptera: Chrysomelidae) on Lythrum salicaria L. and associated plant communities in Michigan. Biol Control 28:78–91CrossRefGoogle Scholar
  46. Lavoie C, Jean M, Delisle F, Létourneau G (2003) Exotic plant species of the St. Lawrence River wetlands: a spatial and historical analysis. J Biogeogr 30:537–549Google Scholar
  47. Lee G (2002) Stimulating political awareness of invasive alien species: lessons learned from Canada’s purple loosestrife initiatives. In: Claudi R, Nantel P, Muckle-Jeffs E (eds) Alien invaders in Canada’s waters, wetlands and forests. Natural Resources Canada, Canadian Forest Service, Science Branch, Ottawa, pp 253–258Google Scholar
  48. Lindgren CJ (2003) Using 1-min scans and stem height data in a post-release monitoring strategy for Galerucella calmariensis (L.) (Coleoptera: Chrysomelidae) on purple loosestrife, Lythrum salicaria L. (Lythraceae), in Manitoba. Biol Control 27:201–209CrossRefGoogle Scholar
  49. Louis-Marie P (1944) La Salicaire dans le Québec. Institut agricole d’Oka, OkaGoogle Scholar
  50. Mack RN (1991) The commercial seed trade: an early disperser of weeds in the United States. Econ Bot 45:257–273Google Scholar
  51. Maddox JD, Wiedenmann RN (2005) Nesting of birds in wetlands containing purple loosestrife (Lythrum salicaria) and cattail (Typha spp.). Nat Areas J 25:369–373Google Scholar
  52. Maerz JC, Brown CJ, Chapin CT, Blossey B (2005) Can secondary compounds of an invasive plant affect larval amphibians? Funct Ecol 19:970–975CrossRefGoogle Scholar
  53. Mahaney WM, Smemo KA, Yavitt JB (2006) Impacts of Lythrum salicaria invasion on plant community and soil properties in two wetlands in central New York, USA. Can J Bot 84:477–484CrossRefGoogle Scholar
  54. Mal TK, Lovett-Doust J, Lovett-Doust L, Mulligan GA (1992) The biology of Canadian weeds. 100. Lythrum salicaria. Can J Plant Sci 72:1305–1330Google Scholar
  55. Mal TK, Lovett-Doust J, Lovett-Doust L (1997) Time-dependent competitive displacement of Typha angustifolia by Lythrum salicaria. Oikos 79:26–33CrossRefGoogle Scholar
  56. Malecki RA, Blossey B, Hight SD, Schroeder D, Kok LT, Coulson JR (1993) Biological control of purple loosestrife. Bioscience 43:680–686CrossRefGoogle Scholar
  57. McCullough DG, Work TM, Cavey JF, Liebhold AM, Marshall D (2006) Interceptions of nonindigenous plant pests at US ports of entry and border crossings over a 17-year period. Biol Invasions 8:611–630CrossRefGoogle Scholar
  58. Morrison JA (2002) Wetland vegetation before and after experimental purple loosestrife removal. Wetlands 22:159–169CrossRefGoogle Scholar
  59. Osgood DT, Yozzo DJ, Chambers RM, Jacobson D, Hoffman T, Wnek J (2003) Tidal hydrology and habitat utilization by resident nekton in Phragmites and non-Phragmites marshes. Estuaries 26:522–533CrossRefGoogle Scholar
  60. Perrings C, Dehnen-Schmutz K, Touza J, Williamson M (2005) How to manage biological invasions under globalization. Trends Ecol Evol 20:212–215CrossRefPubMedGoogle Scholar
  61. Pyšek P, Richardson DM, Pergl J, Jarošik V, Sixtová Z, Weber E (2008) Geographical and taxonomic biases in invasion ecology. Trends Ecol Evol 23:237–244CrossRefPubMedGoogle Scholar
  62. Rachich J, Reader RJ (1999) An experimental study of wetland invisibility by purple loosestrife (Lythrum salicaria). Can J Bot 77:1499–1503CrossRefGoogle Scholar
  63. Rawinski TJ, Malecki RA (1984) Ecological relationships among purple loosestrife, cattail and wildlife at the Montezuma National Wildlife Refuge. New York Fish Game J 31:81–87Google Scholar
  64. Schooler SS, McEvoy PB, Coombs EM (2006) Negative per capita effects of purple loosestrife and reed canary grass on plant diversity of wetland communities. Divers Distrib 12:351–363CrossRefGoogle Scholar
  65. Schooler SS, McEvoy PB, Hammond P, Coombs EM (2009) Negative per capita effects of two invasive plants, Lythrum salicaria and Phalaris arundinacea, on the moth diversity of wetland communities. B Entomol Res 99:229–243CrossRefGoogle Scholar
  66. Scudder T, Huffman R, Lukaszewski J, Elsner S, Kolodziej M, Palmer D, Mayer M (2006) Release of Galerucella calmariensis and Galerucella pusilla (Coleoptera: Chrysomelidae) to control purple loosestrife, Lythrum salicaria. New Jersey Department of Agriculture, Division of Plant Industry, Phillip Alampi Beneficial Insect Laboratory, 2006 Report, TrentonGoogle Scholar
  67. Silliman BR, Bertness MD (2004) Shoreline development drives invasion of Phragmites australis and the loss of plant diversity on New England salt marshes. Conserv Biol 18:1424–1434CrossRefGoogle Scholar
  68. Simberloff D, Gibbons L (2004) Now you see them, now you don’t!—population crashes of established introduced species. Biol Invasions 6:161–172CrossRefGoogle Scholar
  69. Stuckey RL (1980) Distributional history of Lythrum salicaria (purple loosestrife) in North America. Bartonia 47:3–20Google Scholar
  70. Templer P, Findlay S, Wigand C (1998) Sediment chemistry associated with native and non-native emergent macrophytes of a Hudson River marsh ecosystem. Wetlands 18:70–78CrossRefGoogle Scholar
  71. Thompson DQ, Stuckey RL, Thompson EB (1987) Spread, impact, and control of purple loosestrife (Lythrum salicaria) in North American wetlands. United States Department of the Interior, Fish and Wildlife Service. Fish and Wildlife Research no. 2, Washington (DC)Google Scholar
  72. Thomson Reuters (2008) Web of science. Available via
  73. Torrey RH (1929) Field meeting of Sunday August 18. Torreya 29:143–144Google Scholar
  74. Treberg MA, Husband BC (1999) Relationship between the abundance of Lythrum salicaria (purple loosestrife) and plant species richness along the Bar River, Canada. Wetlands 19:118–125CrossRefGoogle Scholar
  75. United States Department of Agriculture (2008) Germplasm resources information network. Available via
  76. Valéry L, Fritz H, Lefeuvre J-C, Simberloff D (2008) In search of a real definition of the biological invasion phenomenon itself. Biol Invasions 10:1345–1351CrossRefGoogle Scholar
  77. Weihe PE, Neely RK (1997) The effects of shading on competition between purple loosestrife and broad-leaved cattail. Aquat Bot 59:127–138CrossRefGoogle Scholar
  78. Weiher E, Wisheu IC, Keddy PA, Moore DRJ (1996) Establishment, persistence, and management implications of experimental wetland plant communities. Wetlands 16:208–218CrossRefGoogle Scholar
  79. Welsch M, Yavitt JB (2003) Early stages of decay of Lythrum salicaria L. and Typha latifolia in a standing-dead position. Aquat Bot 75:45–57CrossRefGoogle Scholar
  80. Welsch M, Yavitt JB (2007) Microbial CO2 production, CH4 dynamics and nitrogen in a wetland soil (New York State, USA) associated with three plant species (Typha, Lythrum, Phalaris). Eur J Soil Sci 58:1493–1505CrossRefGoogle Scholar
  81. Westphal MI, Browne M, MacKinnon K, Noble I (2008) The link between international trade and the global distribution of invasive alien species. Biol Invasions 10:391–398CrossRefGoogle Scholar
  82. Whitt MB, Prince HH, Cox RR (1999) Avian use of purple loosestrife dominated habitat relative to other vegetation types in a Lake Huron wetland complex. Wilson Bull 111:105–114Google Scholar
  83. Windham L, Lathrop RG (1999) Effects of Phragmites australis (common reed) invasion on aboveground biomass and soil properties in brackish tidal marsh of the Mullica River, New Jersey. Estuaries 26:452–464CrossRefGoogle Scholar
  84. Yakimowski SB, Hager HA, Eckert CG (2005) Limits and effects of invasion by the nonindigenous wetland plant Lythrum salicaria (purple loosestrife): a seed bank analysis. Biol Invasions 7:687–698CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.École supérieure d’aménagement du territoire et de développement régionalUniversité LavalQuebec CityCanada

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