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| ## purple loosestrife {#purple-loosestrife .Title-Header}             |
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| *Lythrum salicaria* L.                                                |
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| Plant Symbol = LYSA2                                                  |
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Contributed by: USDA NRCS National Plant Data Center & Louisiana State
University-Plant Biology; partial funding from the US Geological Survey
and the US National Biological Information Infrastructure

### ![](media/image2.jpeg){width="2.6979166666666665in" height="4.0465277777777775in"}

# Alternate Names

purple loosestrife, spiked lythrum, salicaire, bouquet violet

# Uses

**Noxious and highly invasive.**

*Ethnobotanic*: Immigrants might have deliberately introduced *L.
salicaria* for its value as a medicinal herb in treating diarrhea,
dysentery, bleeding wounds, ulcers, and sores, for ornamental purposes,
or as a source of nectar and pollen for beekeepers (Hayes 1979; Jones
1976; Malecki et al. 1993; Stuckey 1980). In states where it is
permitted, purple loosestrife continues to be promoted by
horticulturists for its beauty as a landscape plant and for bee-forage.
Purple loosestrife has been of interest to beekeepers because of its
nectar and pollen production. However, honey produced from it is
apparently of marginal quality (Feller-Demalsy & Parent 1989).

*Horticultural*: Horticultural cultivars of purple loosestrife
(*Lythrum* spp.) were developed in the mid-1900s for use as ornamentals.
Initially, these were thought to be sterile, and therefore safe for
horticultural use. Recently, under greenhouse conditions, experimental
crosses between several cultivars and wild purple loosestrife and the
native *L. alatum* produced hybrids that were highly fertile (Ottenbreit
1991; Ottenbreit & Staniforth 1994). Comparable, subsequent experiments
performed under field conditions produced similar results, suggesting
that cultivars of purple loosestrife can contribute viable seeds and
pollen that can contribute to the spread of purple loosestrife (Lindgren
& Clay 1993). Ottenbreit & Staniforth (1994) indicate that such results
suggest the need to prohibit cultivars of this species.

*Noxiousness*: Purple loosestrife grows most abundantly in parts of
Canada, the northeastern United States, the Midwest, and in scattered
locations in the West. Although this species tolerates a wide variety of
soil conditions, its typical habitat includes cattail marshes, sedge
meadows, and bogs. It also occurs along ditch, stream, and riverbanks,
lake shores, and other wet areas. In such habitats, purple loosestrife
forms dense, monospecific stands that can grow to thousands of acres in
size, displacing native, sometimes rare, plant species and eliminating
open water habitat. The loss of native species and habitat diversity is
a significant threat to wildlife, including birds, amphibians, and
butterflies, that depend on wetlands for food and shelter. Purple
loosestrife monocultures also cause agricultural loss of wetland
pastures and hay meadows by replacing more palatable native grasses and
sedges (Mal et al. 1992; Thompson et al. 1987).

Having a noxious weed designation in some states prohibit its
importation and distribution, but it is readily available commercially
in many parts of the country. *Lythrum salicaria* has been labeled the
"purple plague.\" because of its epidemic devastation to natural
communities. The species is included on the Nature Conservancy's list of
"America's Least Wanted -The Dirty Dozen" (Flack & Furlow 1996).

*Impact/Vectors*: Naturalized purple loosestrife was relatively obscure
from the time of its introduction into North America in the early 1800s
(Pursh 1814) until 1930, when a significant increase in populations
invading wetlands and pastures was documented (Strefeler et al. 1996b).
Reasons for the apparent sudden colonization and spread of this species
include the disturbance of natural systems by human activities including
agricultural settlement, construction of transport routes such as
canals, highways, and perhaps, nutrient increases to inland waters (Mal
et al. 1992; Malecki et al. 1993). Absence of natural enemies and
ornamental use are other possible causes for purple loosestrife's rapid
expansion in North America (Thompson et al, 1987). Recently created
irrigation systems in many western states have supported further
establishment and spread of *L*. *salicaria* (Malecki et al. 1993).

The acquisition of adaptive characteristics from native species of
*Lythrum* may have enhanced purple loosestrife's invasive success. It
will hybridize with *Lythrum alatum,* a widespread, native North
American species, in natural settings. Under certain circumstances
fertile hybrids are produced that can cross with weedy purple
loosestrife. Such interspecific hybrids could serve as a "hybrid bridge"
for the transfer of adaptive traits from native *L. alatum* into weedy
populations of purple loosestrife (Anderson & Ascher 1993; Strefeler et
al. 1996b).

North American naturalized populations of purple loosestrife often form
monospecific stands, whereas, in its native Eurasian habitat the species
comprises 1-4% of the vegetative cover (Batra et al. 1986; Strefeler et
al. 1996b). Purple loosestrife causes annual wetland losses of about
190,000 hectares in the United States (Thompson et al. 1987; Mal et al.
1997). The species is most abundant in the Midwest and Northeast where
it infests about 8,100 hectares in Minnesota, 12,000 ha in Wisconsin,
over 12,000 ha in Ohio, and a larger area in New York State. Recent
distributional surveys document the occurrence of monocultures in every
county in Connecticut, where it has been found in 163 wetland locations
(Ellis and Weaver 1996; Ellis 1996). At the Effigy Mounds National
Monument (EFMO), combined populations of purple loosestrife cover an
area of 5 to 10 hectares growing in regularly disturbed sites. This
species has a major visual impact on the vegetation of EFMO, and it has
the potential to invade and replace native communities endangering the
areas\' primary resources. (Butterfield et al. 1996). In response to the
alarming spread of this exotic species, at least 13 states (e.g.,
Minnesota, Illinois, Indiana, Ohio, Washington, and Wisconsin) have
passed legislation restricting or prohibiting its importation and
distribution (Malecki et al. 1993; Strefeler et al. 1996b).

Numerous studies demonstrate the aggressive and competitive nature of
purple loosestrife. Fernald (1940) reported a loss of native plant
diversity in the St. Lawrence River floodplain following the invasion of
purple loosestrife and another exotic, *Butomus* *umbellatus* L. Gaudet
and Keddy (1988) report declining growth for 44 native wetland species
after the establishment of *Lythrum*. Among the species tested, Keddy
(1990) found that purple loosestrife was the most competitive. His
hierarchical rank, arranged from most to least competitive, illustrates
the dominance of this invasive weed over many common natives:
*Lythrum\>Cyperus\>Juncus\> Eleocharis\> Mimulus\>Verbena.* In the
Hamilton Marshes adjacent to the Delaware River, annual above-ground
production of *L. salicaria* far exceeded all other plant species'
production combined.

Purple loosestrife provides little food, poor cover, and few nesting
materials for wildlife (Mann 1991). Waterfowl nesting becomes more
difficult as clumps of *L. salicaria* restrict access to open water and
offer concealing passageways for predators such as foxes and raccoons
(Mal et al. 1992). Non-game species, including black terns and marsh
wrens, also lose nesting sites when purple loosestrife infests their
normal habitats. Balogh and Bookhout (1989a) report that dense stands of
purple loosestrife provide poor waterfowl and muskrat habitat. Red-wing
blackbirds appear to be the only species to cope with changes in
wetlands caused by purple loosestrife (Balogh and Bookhout 1989a). In
many areas where *L. salicaria* populations have increased, wildlife
species have declined. While some studies may fail to demonstrate cause
and affect relationship, they firmly establish circumstantial evidence
implicating that *Lythrum'*s invasion is responsible for major changes
in wetland communities (Mal et al. 1992).

Purple loosestrife prefers moist, highly organic soils but can tolerate
a wide range of conditions. It grows on calcareous to acidic soils, can
withstand shallow flooding, and tolerates up to 50% shade. Purple
loosestrife has low nutrient requirements and can withstand nutrient
poor sites. Under experimental, nutrient-deficient conditions, the
root/shoot ratio increased and provided purple loosestrife with a
competitive advantage over the native species *Epilobium hirsutum.*
Survival and growth of *L. salicaria* was greatly improved by fertilizer
treatment and greater spacing between plants. Such results suggest that
excessive use of fertilizers and the release of phosphates, nitrates,
and ammonia into the environment has enhanced the success of *Lythrum*
(Mal et al., 1992; Shamsi and Whitehead, 1977a and b).

Purple loosestrife flowers from July until September or October.
Flowering occurs 8-10 weeks after initial spring growth. The lowermost
flowers of the inflorescence open first and flowering progresses upward.
The capsules mature in the same sequence and the lowermost will ripen
and disperse its seeds while flowering is still occurring further up the
inflorescence (Butterfield et al. 1996). Thompson et al. (1987)
estimated that on average, a mature plant produces about 2,700,000 seeds
annually. Purple loosestrife seeds are mostly dispersed by water, but
wind and mud adhering to wildlife, livestock, vehicle tires, boats, and
people serve also as agent. Seeds are relatively long-lived, retaining
80% viability after 2-3 years of submergence (Malecki 1990). Welling &
Becker (1990) investigated seed bank dynamics in three wetland sites in
Minnesota and noted a mean density of 410,000 seeds per square meter in
the top 5 cm of soil, which was more than all other species combined.

Spring-germinated seedlings have a higher survival rate than
summer-germinated seedlings. Seedlings that germinate in the spring will
flower the first year, whereas, summer-germinated seedlings develop only
five or six pairs of leaves before the end of the growing season. Since
its seeds are small, weighing about 0.06 mg each and carry little food
reserves, germination must occur under conditions where photosynthesis
can occur immediately. A strong taproot develops quickly in seedlings
and persists throughout the life of the plant. The aerial shoots die in
the fall and new shoots arise the following spring from buds on the
rootstocks. Shoots destroyed by fire, herbicides, or mechanical removal
can also regenerate from the rootstock. As plants mature, they produce
more and more aerial shoots forming very dense clumps of growth. Purple
loosestrife can spread vegetatively by resprouting from stem cuttings
and from regeneration of pieces of root stock (Mal et al. 1992).
Rhizomatous growth is insignificant in purple loosestrife (Shamsi &
Whitehead 1974a; Thompson et al. 1987).

# Status

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status, such as, state noxious
status, and wetland indicator values.

# Description

*General*: Loosestrife Family (Lythraceae). Purple loosestrife is an
erect perennial herb that grows up to 2.5 m tall, develops a strong
taproot, and may have up to 50 stems arising from its base. Its 50 stems
are four-angled and glabrous to pubescent. Its leaves are sessile,
opposite or whorled, lanceolate (2-10 cm long and 5-15 mm wide), with
rounded to cordate bases. Leaf margins are entire. Leaf surfaces are
pubescent.

Each inflorescence is spike-like (1-4 dm long), and each plant may have
numerous inflorescences. The calyx and corolla are fused to form a
floral tube (also called a hypanthium) that is cylindrical (4-6 mm
long), greenish, and 8-12 nerved. Typically the calyx lobes are narrow
and thread-like, six in number, and less than half the length of the
petals. The showy corolla (up to 2 cm across) is rose-purple and
consists of five to seven petals. Twelve stamens are typical for each
flower. Individual plants may have flowers of three different types
classified according to stylar length as short, medium, and long. The
short-styled type has long and medium length stamens, the medium type
has long and short stamens, and the long-styled has medium to short
stamens. The fruit is a capsule about 2 mm in diameter and 3-4 mm long
with many small, ovoid dust-like seeds (\< 1 mm long).

Mal et al., 1992, provide a detailed morphological description for L.
salicaria. The authors also give details of the tristylous features of
this species, as well as an account of its pollen structure and
chromosome numbers. The plant's habit, vegetative, and reproductive
structures are illustrated with line drawings.

Other species of *Lythrum* that grow in the United States have 1-2
flowers in each leaf-like inflorescence bract and eight or fewer stamens
compared to *L. salicaria,* which has more than two flowers per bract
and typically twelve stamens per flower. *Lythrum virgatum*, another
species introduced from Europe closely resembles *L. salicaria*, but
differs in being glabrous (lacking plant hairs), and having narrow leaf
bases. The latter two species interbreed freely producing fertile
offspring, and some taxonomists (Rendall 1989) consider them to be a
single species.

*Distribution*: Purple loosestrife is a hardy perennial herb with
stunning spikes of purple flowers. A native of Eurasia, it was
introduced to North America in the early 1800\'s where it first appeared
in ballast heaps of eastern harbors (Stuckey 1980). Most likely seeds
were transported as contaminants in the ballast or possibly attached to
raw wool or sheep imported from Europe (Cole, 1926; Thompson et al.,
1987).

The native range of *L. salicaria* is thought to extend from Great
Britain to central Russia from near the 65th parallel to North Africa.
It also occurs in Japan, Korea, and the northern Himalayan region. The
species has been introduced to Australia, Tasmania, and New Zealand.
Since its introduction to North America, this alien plant has spread
rapidly into Canada, and throughout most of the United States where it
has been reported from all states except Alaska, Florida, Louisiana, and
South Carolina. Several factors have contributed to the spread of purple
loosestrife such as its potential for rapid growth, its enormous
reproductive capacity, lack of natural diseases or predators, its use as
an ornamental, and for bee forage (Mal et al. 1992). For current U.S.
distribution, please consult the Plant Profile page for this species on
the PLANTS Web site.

# Control

Please contact your local agricultural extension specialist or county
weed specialist to learn what works best in your area and how to use it
safely. Always read label and safety instructions for each control
method. Trade names and control measures appear in this document only to
provide specific information. USDA, NRCS does not guarantee or warranty
the products and control methods named, and other products may be
equally effective.

An important consideration in controlling purple loosestrife is its
prolific seed production, the ease with which seeds are dispersed, and
their ability to remain viable for several years. Also, this plant can
spread vegetatively by resprouting from stem and rootstock cuttings.
Other considerations in selecting control methods are their detrimental
effects on native species and the possibility for reinvasion by purple
loosestrife or other exotic species. In addition, native plants of
similar appearance should not be subjected to control. Purple
loosestrife may superficially resemble plants of the mint family or
species of the genera *Epilobium* and *Liatris*. Proper identification
is an important consideration in controlling exotic loosestrife.

In natural areas, it may be more feasible to contain populations of
purple loosestrife than control them. Large populations extending over
one hectare or more will be difficult to eradicate. Containing them may
be more feasible. Removing plants or applying herbicides to ones
extending beyond the main population can accomplish this. If loosestrife
cannot be eradicated, efforts should then concentrate on keeping it from
invading the highest quality areas (Butterfield et al., 1996.

*Manual, Mechanical, and Replacement*: Mowing, burning, and flooding are
largely ineffective. Cutting followed by flooding so that cut plant
stalks are completely immersed has shown some success. However, flooding
may encourage the spread of purple loosestrife seed present in the soil
and may result in the regeneration of new plants from stem fragments.
Mature plants can withstand short-term immersion. Burning is largely
ineffective and it may also stress native plants and subsequently
enhance loosestrifes' competitive advantage (Butterfield et al., 1996).

Hand removal is effective for small populations and isolated plants.
Younger plants (one to two years old) can be pulled by hand. Plants
should be removed, prior to seed set, with minimal disturbance to the
soil. Removal after seed-set will scatter the seeds. The entire
rootstock must be pulled out because of the potential for regeneration
from root fragments. A hand cultivator or similar implement will be
helpful for older plants, especially those in deep organic soils.
Uprooted plants and broken stems need to be removed from the site since
such fragments can re-sprout. Bagging plants for removal will prevent
their spread along the exit route. Follow-up treatments are recommended
for three years after plants are removed. Clothing and equipment used
during plant removal should be cleaned to remove contaminating seeds.

Replacement control has been attempted in several wildlife refuges.
Research has shown that Japanese millet (*Echinochloa frumentacea* Link)
seedlings outcompete purple loosestrife seedlings. The millet must be
planted immediately after marsh drawdown and replanted each year because
it does not regenerate well. Replacement seeding trials using native
pale smartweed (*Polygonum lapathifolium* L.) showed that it also
out-competed purple loosestrife. Replacement methods have obvious
limited application in natural areas, but they may provide control of
loosestrife populations on bordering property (Butterfield et al. 1996).

*Herbicide Control*: Various chemical treatments have been used on
purple loosestrife with varying success. Many herbicides are not
specific to purple loosestrife and may not be specifically licensed for
such use. Label directions for application and use according to local,
state, and federal regulations must always be observed.

In areas with populations exceeding 100 plants (up to 1.6 ha in size)
where hand-pulling is not feasible, application of a glyphosate
herbicide to individual purple loosestrife plants provides effective
control Glyphosate is available under the trade names Roundup® and
Rodeo®. Rodeo is registered for use over open water and is the most
commonly used herbicide to control purple loosestrife. Glyphosate is
nonselective and can kill desirable plants associated with loosestrife
if applied carelessly. Application to the tops of plants alone can be
effective and limits exposure of non-target species (Butterfield et al.
1996).

Herbicide treatment should be conducted as early as possible during the
manufacturer\'s recommended time of application in order to kill the
plants and prevent seed production. Application is most effective when
plants have just begun flowering. Timing is important because seed set
can occur if plants are in mid- to late flower. Where possible, the
flower heads should be cut, bagged, and removed from the site prior to
application to prevent seed set. Rodeo applied as a 1.5% solution (2 oz.
Rodeo/gallon clean water) with the addition of a wetting agent, as
specified on the label has been shown to provide control. Another
option, which may be more effective, is to apply glyphosate twice during
the growing season. The plants should be sprayed as described above when
flowering has just started and a second time two to three weeks later
(Butterfield et al. 1996).

Application of ghyphosate from a vehicle-mounted sprayer is generally
necessary in areas with extensive stands of purple loosestrife. The most
effective control can be achieved by beginning treatment at the
periphery of large patches and working toward the center in successive
years. This technique allows native vegetation to re-invade the treated
area as the loosestrife in eliminated (Butterfield et al. 1996).

A combination of 2,4-D and Banvel® (dicamba) has been used on a limited
basis. This formulation is broadleaf specific and apparently would not
hurt the dominants if sprayed in a cattail marsh or communities
dominated by rushes, sedges, and grasses. Spraying produces good control
once loosestrife has reached 10-15% of its mature growth. Treatment is
more effective if repeated once during the growing season (Butterfield
et al. 1996).

*Biological Control*: Several biological control agents have the
potential to aid in the control of purple loosestrife. Of 120 species of
phytophagous insects associated with purple loosestrife in its natural
range in Europe, 14 species were considered host-specific to the target
plant. From this group, six species have been selected as the most
promising for biological control. These species were a root-mining
weevil, *Hylobius transversovittatus* Goeze, which attacks the main
storage tissue of purple loosestrife; two leaf-eating beetles,
*Galerucella calmariensis* L., and *G. pusilla* Duftschmid, which are
capable of completely defoliating the plant; two flower-feeding beetles,
*Nanophyes marmoratus* Goeze and *N. brevis* Boheman, which severely
reduce seed production; and a gall midge, *Bayeriola salicariae*
Kieffer, which similarly reduces seed production by attacking the flower
buds. Five of the six species are found throughout its range in Europe
and the sixth, *N. brevis*, is restricted to southern Europe (Malecki et
al. 1993; Weedin et al. 1996).

The most promising insects appear to be the root-mining weevil, *H.
transversovittatus*, and the two leaf-eating beetles, *G. calmariensis*
and *G. pusilla*, because of their broad geographic ranges and the
amount of damage done to the host plant. In June of 1992, all three
species were approved by USDA, APHIS for introduction into the United
States. The insects were released in New York, Pennsylvania, Maryland,
Virginia, Minnesota, Oregon, and Washington. Releases were also approved
in Canada (Malecki et al. 1993).

The two *Galerucella* species successfully over-wintered and began
oviposition at all release sites. The other species, *H.
transversovittatus*, was proving more difficult to establish, because of
its long life cycle and low fecundity. The investigators predict that
all three species will become established throughout the North American
range of purple loosestrife. Furthermore, *H. transversovittatus* is
expected to have the greatest negative impact to *L. salicaria.*
However, a combination of various phytophagous insects will provide
greater control than any one species. Control of purple loosestrife will
be achieved more rapidly in mixed plant communities where competition
for space and nutrients is greater. A reduction in the abundance of
purple loosestrife to approximately 10% of its current level over about
90% of its range is expected (Malecki et al. 1993).

In order to evaluate the potential of fungus pathogens to control purple
loosestrife, a survey was conducted on fungi associated with that plant.
During the three year study, 5265 fungal isolates were obtained.
Thirty-one taxa were found that had not previously been reported from
purple loosestrife. Tests for the pathogenicity to purple loosestrife
are being tested (Nyvall 1995).

# Illustrations and Photographs: 

Gleason, H. A. 1952. *Illustrated flora of the northeastern United
States and adjacent Canada*. Lancaster Press, Inc., Lancaster,
Pennsylvania. (line drawing, Vol. 3, p. 53).

Mal, T.K., J. Lovett-Doust, L. Lovett-Doust, & G.A. Mulligan 1992. *The
biology of Canadian weeds. 100. Lythrum salicaria*. Can. J. Plant Sci.
Rev. Can. Phytotech. 72(4):1305-1330. Agricultural Institute of Canada,
Ottawa, Ontario, Canada. (detailed line illustrations of the whole plant
and flower morphs).

O\'Neil, P. 1992. *Variation in male and female reproductive success
among floral morphs in the tristylous plant Lythrum salicaria
(Lythraceae)*. American J. of Botany 79(9):1024-1030. Botanical Society
of America, Columbus, Ohio (detailed illustration of the three
(tristyly) flower morphs).

Radford, A. E., H. E. Ahles, & C. R. Bell 1968. *Manual of the vascular
flora of the Carolinas*. University of North Carolina Press, Chapel
Hill, North Carolina. (small line drawing, p. 831).

Randall, J. M. & J. Marinelli 1996. *Invasive plants, weeds of the
global garden.* Brooklyn Botanic Garden, Handbook #149, Brooklyn, New
York. 99 p. (photographs of plants in flower, front cover, p. 5 and p.
81; infested habitat, p. 5).

USDA, NRCS 2000. *The PLANTS database*. Version: 000412.
\<http://plants.usda.gov\>. National Plant Data Center, Baton Rouge,
Louisiana.

USDA, NRCS 2000. *Wetland flora CD-ROM*.
\<http://www.pwrc.usgs.gov/wli/wetprods.htm\>. Wetland Science
Institute, Laurel, Maryland.

# References

Anderson, N.O. & P.D. Ascher 1993. *Male and female fertility of
loosestrife (Lythrum) cultivars*. Journal of the American Horticulture
Society 118(6):851-858.

Balogh, G.R. & T.A. Bookhout 1989a. *Purple loosestrife (Lythrum
salicaria) in Ohio\'s Lake Erie marshes*. Ohio Journal of Science
89(3):62-64. maps.

Batra, S.W.T., D. Schroeder, P.E. Boldt, & W. Mendel 1986. *Insects
associated with purple loosestrife (Lythrum salicaria L.) in Europe*.
Proc. Entomol. Soc. Wash., 88(4):748-759, Washington, D.C.

Blossey, B. 1993. *Herbivory below ground and biological weed control:
life history of a root-boring weevil on purple loosestrife*. Oecologia
94(3):380-387.

Blossey, B. 1995. *A comparison of various approaches for evaluating
potential biological control agents using insects on Lythrum salicaria*.
Biological Control 5(2):113-122.

Blossey, B. & R.U. Ehlers 1991. *Entomopathogenic nematodes
(Heterorhabditis spp. and Steinernema anomali) as potential antagonists
of the biological weed control agent Hylobius transversovittatus
(Coleoptera: Curculionidae)*. J. Invertebrate Pathology 58(3):453-454.

Blossey, B. & R. Notzold 1995. *Evolution of increased competitive
ability in invasive nonindigenous plants: a hypothesis*. J. Ecology
83(5):887-889.

Blossey, B. & D. Schroeder 1995. *Host specificity of three potential
biological weed control agents attacking flowers and seeds of Lythrum
salicaria (purple loosestrife)*. Biological Control 5(1):47-53.

Blossey, B., D. Schroeder, S.D. Hight, & R.A. Malecki 1994a. *Host
specificity and environmental impact of two leaf beetles (Galerucella
calmariensis and G. pusilla) for biological control of purple
loosestrife (Lythrum salicaria)*. Weed Science 42(1):134-140.

Blossey, B., D. Schroeder, S.D. Hight, & R.A. Malecki 1994b. *Host
specificity and environmental impact of the weevil Hylobius
transversovittatus, a biological control agent of purple loosestrife
(Lythrum salicaria)*. Weed Science 42(1):128-133.

Brungardt, S. \[1992.\] *Wisdom of a flower ban supported by research*.
Minn. Sci. Agric. Exp. Stn. Univ. Minn. 47(1):4-5.

Butterfield, C., J. Stubbendieck, & J. Stumpf 1996. *Species abstracts
of highly disruptive exotic plants*. Version: 16JUL97. Northern Prairie
Wildlife Research Center Home Page, Jamestown, North Dakota.

http://www.npsc.nbs.gov/resource/othrdata/plntguid/species/lythsali.htm.

Cole, A.H. 1926. *The American manufacture*. Vol. 1. Harvard University
Press, Cambridge, Massachusetts.

Cornell University, Educational Television Center and Media Services
1996. *Restoring the balance: biological control of purple loosestrife*.
Ithaca, New York. 1 videocassette (28 min.).

Ellis, D. R. 1996. *Biological control of purple loosestrife in
Connecticut*. 1996 Summary Report.
\<http://www.ceris.purdue.edu/napis/pests/pls/index.html\>. (15 May
1997).

Ellis, D.R. & J.S. Weaver 1996. *Purple loosestrife: Survey and
biological control*. 1995 Summary Report, USDA, APHIS, PPQ, Cooperative
Agricultural Pest Survey (CAPS). 9 pp

Feller Demalsy, M.J. & J. Parent 1989. *Analyse pollinique des miels de
l'Ontario, Canada*. Apidologie 20:127-138.

Fernald, M.L. 1940. *The problem of conserving rare native plants*.
Annual Report, Smithsonian Institution (1939):375-391.

Flack, S. & E. Furlow 1996. *America\'s least wanted \"purple plague,\"
\"green cancer\" and 10 other ruthless environmental thugs*. Nature
Conservancy Magazine 46(6) November/December.
\<http://www.tnc.org/news/magazine/nov_dec/index.html\>.

Gabor, T.S., & H.R. Murkin 1990. *Effects of clipping purple loosestrife
seedlings during a simulated wetland drawdown*. Journal of Aquatic Plant
Management 28:98-100.

Gardner, S.C. & C.E. Grue 1996. *Effects of Rodeo and Garlon 3A on
nontarget wetland species in central Washington*. Environmental
Toxicolog. Chem. 15(4): 441-451.

Gaudet, C.L. & P.A. Keddy 1988. *A comparative approach to predicting
competitive ability from plant traits*. Nature 334(6179):242-243.

Gaudet, C.L. & P.A. Keddy 1995. *Competitive performance and species
distribution in shoreline plant communities: a comparative approach*.
Ecology 76(1):280-291.

Hayes, B. 1979. *Purple loosestrife - The wetlands honey plant*.
American Bee Journal 119:382-383.

Heidorn, R., & B. Anderson 1991. *Vegetation management guideline:
purple loosestrife (Lythrum salicaria L.)*. Natural Areas Journal
11:172-173.

Heuch, I. 1979. *The effect of partial self-fertilization on type
frequencies in heterostylous plants Lythrum salicaria*. Annals of Botany
44(5):611-616. ill.

Hight, S.D., B. Blossey, J. Laing & R. DeClerck-Floate 1995.
*Establishment of insect biological control agents from Europe against
Lythrum salicaria in North America*. Environmental Entomology
24(4):967-977.

Jones, M.A. 1976. *Destination America*. Holt, Rinehart & Winston, New
York, New York.

Katovich, E.J.S., R.L. Becker, & B.D. Kinkaid 1996. *Influence of
nontarget neighbors and spray volume on retention and efficacy of
triclopyr in purple loosestrife (Lythrum salicaria)*. Weed Science
44(1):143-147.

Keddy, C. 1988. *A review of Lythrum salicaria (purple loosestrife)
ecology and management: The urgency for management in Ontario*. Natural
Heritage League, Ottawa, Ontario, Canada. 34 pp.

Keddy, C. 1990. *The use of functional as opposed to phylogenetic
systematics: a first step in predictive community ecology*. IN: S.
Kawano, ed. *Biological approaches and evolutionary trends in plants*.
Academic Press, London, U.K.

Kok, L.T., T.J. McAvoy, R.A. Malecki, S.D. Hight, J.J. Drea, & J.R.
Coulson 1992. *Host specificity tests of Hylobius transversovittatus
Goeze (Coleoptera: Curculionidae), a potential biological control agent
of purple loosestrife, Lythrum salicaria L. (Lythraceae).* Biological
Control 2:1-8.

Kok, L.T., T.J. McAvoy, R.A. Malecki, S.D. Hight, J.J. Drea, & J.R.
Coulson 1992. *Host specificity tests of Galerucella calmariensis (L.)
and G. pusilla (Duft.) (Coleoptera Chrysomelidae), potential biological
control agents of purple loosestrife, Lythrum salicaria L.
(Lythraceae).* Biological Control 2:282-290.

Lindgren, C.J. & R.T. Clay 1993. *Fertility of \'Morden Pink\' Lythrum
virgatum L. transplanted into wild stands of L. salicaria L. in
Manitoba*. HortScience 28(9):954.

Mal, T.K., J. Lovett-Doust, L. Lovett-Doust, & G.A. Mulligan 1992. *The
biology of Canadian weeds. 100.* *Lythrum salicaria*. Can. J. Plant Sci.
Rev. Can. Phytotech. 72(4):1305-1330.

Mal, T.K., J. Lovett-Doust, & L. Lovett-Doust 1997. *Time-dependent
competitive displacement of Typha angustifolia by Lythrum salicaria*.
Oikos 79:26-33.

Malecki, R.A., B. Blossey, S.D. Hight, D. Schroeder, L.T. Kok, & J.R.
Coulson 1993. *Biological control of purple loosestrife*. BioScience
43:680-686.

Malecki, R. 1990. *Research update-Biological control of purple
loosestrife*. Report of New York Cooperative Fish and Wildlife Research
Unit, Cornell University, Ithaca, New York. 4pp + 2 figs.

Malecki, R. 1994. *Insect biological weed control: an important and
underutilized management tool for maintaining native plant communities
threatened by exotic plant introductions*. Trans. North. Am. Wildl. Nat.
Resoures Conf. (59th) p. 400-404. Wildlife Management Institute,
Washington, DC.

Mann, H. 1991. *Purple loosestrife: A botanical dilemma*. The Osprey
22:67-77.

Notestein, A. 1987. *Purple loosestrife managed with herbicides at
Horicon National Wildlife Refuge (Wisconsin)*. Restoration and
Management Notes 5:91.

Nyvall, R.F. 1995. *Fungi associated with purple loosestrife (Lythrum
salicaria) in Minnesota*. Mycologia 87(4):501-506.

Nyvall, R.F. & A. Hu 1997. *Laboratory evaluation of indigenous North
American fungi for biological control of purple loosestrife*. Biological
Control 8(1):37-42.

O\'Neil, P. 1997*. Natural selection on genetically correlated
phenological characters in Lythrum salicaria L. (Lythraceae)*. Evolution
51(1):267-274.

Ottenbreit, K.A. 1991*. The distribution, reproductive biology, and
morphology of Lythrum species, hybrids and cultivars in Manitoba*. M.Sc.
thesis, Department of Botany, University of Manitoba, Winnipeg,
Manitoba, Canada.

Ottenbreit, K.A. & R.J. Staniforth 1994. *Crossability of naturalized
and cultivated Lythrum taxa*. Canadian Journal of Botany 72(3):337-341.

Pursh, F. 1814. *Flora Americae Septentrionalis (or systematic
arrangement and description of the plants of North America)*. White,
Cochrane, and Co., London, England.

Rendall, J. 1989. *The Lythrum story: A new chapter*. Minnesota
Horticulturist 117:22-24.

Shamsi, S.R.A., & F.H. Whitehead 1974a. *Comparative eco-physiology of
Epilobium hirsutum L. and Lythrum salicaria L*. I. IN *General biology,
distribution, and germination*. Journal of Ecology 62:279-290.

Shamsi, S.R.A., & F.H. Whitehead 1974b. *Comparative eco-physiology of
Epilobium hirsutum L. and Lythrum salicaria L*. II. IN *Growth and
development in relation to light*. Journal of Ecology 62:631-645.

Shamsi, S.R.A., & F.H. Whitehead 1977a. *Comparative eco-physiology of
Epilobium hirsutum L. and Lythrum salicaria L*. III. IN *Mineral
nutrition*. Journal of Ecology 65:55-70.

Shamsi, S.R.A., & F.H. Whitehead 1977b. *Comparative eco-physiology of
Epilobium hirsutum L. and Lythrum salicaria L. IV*. IN *Effects of
temperature and inter-specific competition and concluding discussion*.
Journal of Ecology 65:71-84.

Shamsi, S.R.A. 1976. *Effect of a light-break on the growth and
development of Epilobium hirsutum and Lythrum salicaria in short
photoperiods*. Annals of Botany 40(165):153-162.

Strefeler, M.S., E. Darmo, R.L. Becker, & E.J. Katovich 1996a. *Isozyme
variation in cultivars of purple loosestrife (Lythrum sp.)*. HortScience
31(2):279-282.

Strefeler, M.S., E. Darmo, R.L. Becker, & E.J. Katovich 1996b. *Isozyme
characterization of genetic diversity in Minnesota populations of purple
loosestrife, Lythrum salicaria (Lythraceaae).* American Journal of
Botany 83(3):265-273.

Stuckey, R.L. 1980. *Distributional history of Lythrum salicaria (purple
loosestrife) in North America*. Bartonia 17(47):3-20.

Thompson, D.Q. 1991. *History of purple loosestrife (Lythrum salicaria
L.) biological control effects*. Natural Areas Journal 11:148-150.

Thompson, D.Q., R.L. Stuckey, & E.B. Thompson 1987. *Spread, impact, and
control of purple loosestrife (Lythrum salicaria) in North American
wetlands*. Research Report No. 2. USDI, Fish and Wildlife Service,
Washington, DC.

Twolan-Strutt, L. & P.A. Keddy 1996. *Above- and below-ground
competition intensity in two contrasting wetland plant communities*.
Ecology 77(1):259-270.

Voegtlin, D.J. 1995. *Potential of Myzus lythri (Homoptera: Aphididae)
to influence growth and development of Lythrum salicaria (Myrtiflorae:
Lythraceae).* Environmental Entomology 24(3):724-729.

Weeden, C. R, A. M. Shelton, & M. P. Hoffmann, Eds. 1996. *Biological
control: A guide to natural enemies in North America*. Cornell
University.
(http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/galerucella.html;
http://www.nysaes.cornell.edu/ent/biocontrol/
weedfeeders/hylobius.html).

Welling, C.H. & R.L. Becker 1990. *Seed bank dynamics of Lythrum
salicaria L.: implications for control of this species in North
America*. Aquatic Botany 38:303-309.

Wilcox, D.A., M.K. Seeling, & K.R. Edwards 1986. *Ecology and management
potential for purple loosestrife (Lythrum salicaria)*. IN *The George
Wright Society conference on science in the National Parks*. USDI,
National Park Service, Washington, DC.

Wilcox, D.A. 1989. *Migration and control of purple loosestrife (Lythrum
salicaria L.) along highway corridors*. Environmental Management
13(3):365-370.

# Prepared By

Lowell Urbatsch, Department of Plant Biology, Louisiana State
University, Baton Rouge, Louisiana

# Species Coordinator

Mark Skinner, USDA, NRCS, National Plant Data Center, Baton Rouge,
Louisiana

Edited: 19sep00 jsp;05feb03ahv; 060802 jsp

For more information about this and other plants, please contact your
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Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
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\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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