FULL SCIENTIFIC NAME
Lythrum salicaria L.
FAMILY NAME COMMON
FAMILY SCIENTIFIC NAME
Lythrum salicaria is an herbaceous wetland perennial that can grow 0.5-1.5 m (1.5-5 ft.) tall. The leaves are either opposite or in whorls of three. The can be pubescent or glabrous. They are lanceolate to linear in shape and 3-10 cm (1-4 in.) long. The larger leaves can be cordate or clasping at their bases. The flowers are purple, magenta or pink. They are numerous and borne on spikes that are between 10 and 40 cm (4-16 in.) long. The hypanthium is linear and twice as long as the sepals. Each flower has 5-7 petals, and the open flowers measure 7-12 mm (0.3-0.5 in.) in diameter. The relative lengths of styles and stamen in these flowers can vary in three different ways. The flowers are in bloom from July to September. The fruits are capsules, each containing numerous reddish-brown seeds. Page References Bailey 719, Crow & Hellquist 203, Fernald 1048, Gleason & Cronquist 311, Holmgren 292, Magee & Ahles 758, Newcomb 351, Peterson & McKenny 224,288. See reference section below for full citations.
Lythrum alatum Pursch. (winged loosestrife)* Picture of L. alatum Lythrum alatum is a rare plant that could be confused for L. salicaria. Lythrum alatum is usually shorter in stature, being around 40-80 cm (1-2.5 ft.) tall. The leaves of L. alatum are alternately arranged, except for the very lowest ones on the plant. The flowers of L. alatum are solitary in the upper axils while the flowers of L. salicaria are numerous and in a spike-like arrangement.
Lythrum salicaria reproduces through prolific seed dispersal. The seeds usually fall to the ground after they have ripened. They can be moved longer distances by water or by becoming attached to waterfowl.
The native distribution of Lythrum salicaria is central and southern Europe, Great Britain, and parts of Russia. It has been reported from every state in the United States except for Florida, Arizona, Louisiana, Georgia, Alaska and Hawaii. This plant occurs widely in New England.
HISTORY OF INTRODUCTION IN NEW ENGLAND
The first report of Lythrum salicaria in North America was in 1814. Before the year 1900, 14 of 30 populations of this plant were located in estuaries from Massachusetts to New Jersey. The location of these sites would indicate that the plant was introduced somewhere in this area. There are several hypotheses on how this plant was originally introduced. It could have been a part of ship ballast from Europe, or attached to sheep. Lythrum salicaria was also planted as a source of nectar for beekeeping, as an ornamental, and for medicinal reasons. By the 1900's there were more inland populations being reported, one of these being in New Hampshire. Since these initial introductions it has spread by being planted in gardens and by waterways.
HABITATS IN NEW ENGLAND,Coastal Grassland,Herbaceous Wetland,Lake or Pond,River or Stream,Shrub Wetland,Wet Meadow,Yard or Garden
Lythrum salicaria is most often found in situations where the soil is moist. However, it prefers areas with shallow water, and does not grow as prolifically in deep-water situations.
Lythrum salicaria has the ability to completely dominate wetlands, forming a vast, monotypic stands. These stands prevent the establishment of native wetland plants. It can also have an effect on native wildlife that may not be able to use the plants as effectively for food or cover. By forming these dense stands, Lythrum salicaria can clog waterways, causing problems for both commercial and recreational uses of these areas. Lythrum salicaria can produce up to 2.5 million seeds per plant. Thes seeds persist in the seed bank for years, even if the plants themselves are eradicated from an area. This plant can hybridize with a native loosestrife, L. alatum, which is considered rare in Connecticut. With repeated hybridizations, it is possible that the gene pool for L. alatum could be depleted.
Illinois Natural History Survey
General description and management guidelines
The Connecticut Invasive Plant Working Group
Invasive Plant Management Guide
Plant Conservation Alliance
Fact sheet with management information
Documentation required: A photograph of the plant habit, flowers or fruit.
Best time for documentation: Summer, fall.
Integrated Taxonomic Information System
General information and map
The Nature Conservancy
Extensive description, biology, photographs and control information
Plant Conservation Alliance
Fact sheet that includes images and control information
Virginia Native Plant Society
General information including control
Ohio Perennial and Biennial Weed Guide
Photographs and description
Wisconsin Department of Natural Resources
Description, biology and control information
National Invasive Species Information Center
Links to more information
Illinois Nature Preserves Commission
General information and control
Adirondack Park Invasive Plant Program
Identification, fact sheet, management and distribution information
Anderson, M.G. 1995. Interactions between Lythrum salicaria and native organisms: a critical review. Environment Management 19: 225-231. Anderson, N.O. and P.D. Ascher. 2000. Fecundity and fitness in cross-compatible pollinations of tristylous North American Lythrum salicaria populations. Theoretical and Applied Genetics 101 (5-6): 830-843. Agren, J. 1996. Population size, pollinator limitation, and seed set in the self-incompatible herb Lythrum salicaria. Ecology 77 (6): 1779-1790. Agren, J. and L. Ericson. 1996. Population structure and morph-specific fitness differences in tristylous Lythrum salicaria. Evolution 50 (1): 126-139. Bailey, L.H. 1949. Manual of Cultivated Plants. Macmillan, New York. Blossey, B. 1996. Lythrum salicaria, p.81. In Randall, J.M. and J. Marinelli. [eds.]. Invasive Plants: Weeds of the Global Garden. Brooklyn Botanic Garden Inc., New York. Blossey, B., D. Eberts, E. Morrison, T.R. Hunt. 2000. Mass rearing the weevil Hylobius transversovittatus (Coleoptera : Curculionidae), biological control agent of Lythrum salicaria, on semiartificial diet. Journal of Economic Entomology 93 (6): 1644-1656. Brown, B.J. and C.E. Wickstrom. 1997. Adventitious root production and survival of purple loosestrife (Lythrum salicaria) shoot sections. Ohio Journal of Science 97 (1): 2-4. Britton, N.L. and A. Brown. 1970. An Illustrated Flora of the Northeastern United States vol. 2. Dover Publications Inc., New York. Crow G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. Vol #1. University of Wisconsin Press, Madison. Eckert, C.G., D. Manicacci, S.C.H. Barrett. 1996. Genetic drift and founder effect in native versus introduced populations of an invading plant, Lythrum salicaria (Lythraceae). Evolution 50 (4): 1512-1519. Edwards, K.R., M.S. Adams, J. Kvet. 1995. Invasion history and ecology of Lythrum salicaria in North America. In: Pysek, P. et al. (eds) Plant invasions: general aspects and special problems. SPB Academic Publishing, Amsterdam, pp. 161-180. Edwards, K.R., J. Kvet, M.S. Adams. 1999. Comparison of Lythrum salicaria L. Study sites in the midwest US and central Europe. Ekologia Bratislava 18 (2): 113-124. Farnsworth, E.J. and D.R. Ellis. 2001. Is purple loosestrife (Lythrum salicaria) an invasive threat to freshwater wetlands? Conflicting evidence from several ecological metrics. Wetlands 21 (2): 199-209. Fernald, M.L. 1950. Gray's Manual of Botany 8th ed. American Book Co., Boston. Gabor, T.S. and H.R. Murkin. 1990. Effects of clipping purple loosestrife seedlings during a simulated wetland drawdown. Journal of Aquatic Plant Management 28: 98-100. Gabor, T.S., T. Haagsma, H.R. Murkin. 1996. Wetland plant responses to varying degrees of purple loosestrife removal in southeastern Ontario, Canada. Wetlands 16 (1): 95-98. Galatowitsch, S.M., N.O. Anderson, P.D. Ascher. 1999. Invasiveness in wetland plants in temperate North America. Wetlands 19(4): 733-755. Gleason H.A. and A.C. Cronquist. 1991. Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden, Bronx, New York. Grabas, G.P. and T.M. Laverty. 1999. The effect of purple loosestrife (Lythrum salicaria L. Lythraceae) on the pollination and reproductive success of sympatric co-flowering wetland plants. Ecoscience 6 (2): 230-242. Hager, H.A. and K.D. McCoy. 1998. The implications of accepting untested hypotheses: a review of the effects of purple loosestrife (Lythrum salicaria) in North America. Biodiversity and Conservation 7 (8): 1069-1079. Hamback, P.A., J. Agren, L. Ericson. 2000. Associational resistance: Insect damage to purple loosestrife reduced in thickets of sweet gale. Ecology 81 (7): 1784-1794. Hight, S.D. and J.J. Drea. 1991. Prospects for a classical biological control project against purple loosestrife (Lythrum salicaria L.) Natural Areas Journal 11: 151-157. Holmgren N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. New York Botanical Garden, Bronx, New York. Katovich, E.J.S., R.L. Becker, D.W. Ragsdale. 1999. Effect of Galerucella sp. on survival of purple loosestrife (Lythrum salicaria) roots and crowns. Weed Science 47 (3): 360-365. Lindgren, C.J., T.S. Gabor, H.R. Murkin. 1999. Compatibility of glyphosate with Galerucella calmariensis; a biological control agent for purple loosestrife (Lythrum salicaria). Journal of Aquatic Plant Management 37: 44-48. Magee D.W and H.E. Ahles. 1999. Flora of the Northeast. University of Massachusetts Press, Amherst. Mal, T.K., J. Lovett-Doust, L. Lovett-Doust, G.A. Mulligan. 1992. The biology of Canadian weeds. 100. Lythrum salicaria. Canadian Journal of Plant Science 72: 1305-1330. Mal, T.K., J. Lovett-Doust, L. Lovett-Doust. 1999. Maternal and paternal success among flower morphs in tristylous Lythrum salicaria. Aquatic Botany 63 (3-4): 229-239. Mal, T.K., J. LovettDoust, L. LovettDoust. 1997. Time-dependent competitive displacement of Typha angustifolia by Lythrum salicaria. Oikos 79 (1): 26-33. Mal, T.K., J. LovettDoust, L. LovettDoust. 1997. Effect of soil moisture and fertilizer application on clonal growth and reproduction in a tristylous weed, Lythrum salicaria. Canadian Journal of Botany-Revue Canadienne De Botanique 75 (1): 46-60. McCaughey, T.L. and G.R. Stephenson. 2000. Time from flowering to seed viability in purple loosestrife (Lythrum salicaria). Aquatic Botany 66 (1): 57-68. Mitich, L.W. 1999. Purple loosestrife, Lythrum salicaria L. Weed Technology 13 (4): 843-846. Mullin, B.H. 1998. The biology and management of purple loosestrife (Lythrum salicaria). Weed Technology 12 (2): 397-401. Philip, L.J., U. Posluszny, J.N. Klironomos. 2001. The influence of mycorrhizal colonization on the vegetative growth and sexual reproductive potential of Lythrum salicaria L. Canadian Journal of Botany-Revue Canadienne De Botanique 79 (4): 381-388. Newcomb N. 1977. Newcomb's Wildflower Guide. Little Brown, Boston. Notzold, R., B. Blossey, E. Newton. 1998. The influence of below ground herbivory and plant competition on growth and biomass allocation of purple loosestrife. Oecologia 113 (1): 82-93. Peterson R.T. and M. McKenny. 1968. A field Guide to Wildflowers of Northeastern and North-central North America. Houghton Mifflin, Boston. Piper, G.L. 1996. Biological control of the wetlands weed purple loosestrife (Lythrum salicaria) in the Pacific northwestern United States. Hydrobiologia 340 (1-3): 291-294. Rachich, J. and R.J. Reader. 1999. An experimental study of wetland invasibility by purple loosestrife (Lythrum salicaria). Canadian Journal of Botany-Revue Canadienne De Botanique 77 (10): 1499-1503. Stevens, K.J., R.L. Peterson, G.R. Stephenson. 1997. Vegetative propagation and the tissues involved in lateral spread of Lythrum salicaria. Aquatic Botany 56 (1): 11-24. Stevens, K.J., R.L. Peterson, G.R. Stephenson. 1997. Morphological and anatomical responses of Lythrum salicaria L (purple loosestrife) to an imposed water gradient. International Journal of Plant Sciences 158 (2): 172-183. Thompson, D.Q. 1991. History of purple loosestrife (Lythrum salicaria L.) biological control efforts. Natural Areas Journal 11: 148-157. Treberg, M.A. and B.C. Husband. 1999. Relationship between the abundance of Lythrum salicaria (purple loosestrife) and plant species richness along the Bar River, Canada. Wetlands 19 (1): 118-125. USDA, NRCS. 2001. The PLANTS Database, Version 3.1. (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. Weihe, P.E. and R.K. Neely. 1997. The effects of shading on competition between purple loosestrife and broad-leaved cattail. Aquatic Botany 59 (1-2): 127-138. White, J.A. and I. Charvat. 1999. The mycorrhizal status of an emergent aquatic, Lythrum salicaria L., at different levels of phosphorus availability. Mycorrhiza 9 (4): 191-197.