THE PURPLE MONSTER
By John Brunner
With top billing in the The Weed Hall of Shame, purple loosestrife
has a growing legion of enemies who plot to wipe out the pest-plant
known as Beautiful Killer and Purple Monster.
Purple loosestrife (Lythrum salicaria) is a perennial wetland
plant that is native to Europe and Eurasia. It is an outstandingly
attractive perennial herb with a square, woody stem and opposite,
lance-shaped leaves. The leaves are stalkless and rounded at the
base. Loosestrife plants grow from four to ten feet high and produce
striking magenta-colored flower spikes from July through September.
Purple loosestrife has a long history of use as a medicinal herb
for treatment of diarrhea, dysentery, bleeding wounds and ulcers.
The ancient Greeks used the plant to make hair dye and burned
it as an insect repellent. Modern-day herbalists recommend an
infusion of the leaves and flowers for everything from a gargle
for sore throats to use as a douche.
Purple loosestrife was introduced to the East Coast of North
America in the 1800's as a garden flower, and it may have been
introduced to coastal areas via ship ballast. As valued as the
plant is within its native range, purple loosestrife is on the
hit list of biologists all over the US and Canada, and for good
reason.
The plant adapts readily to open wetlands that allow ample exposure
to the sun (it does not proliferate in shady, forested wetlands).
An invasion of the Purple Monster into a wetland can result in
the destruction of the resident plant community and the eventual
alteration of the wetland's structure and function. Large stands
threaten native wetland plants and wildlife by eliminating natural
foods and cover.
Two characteristics enable purple loosestrife to out-compete
and replace native grasses, sedges, and other flowering plants.
The flowers are insect pollinated and an individual plant produces
millions of tiny seeds that are easily airborne and transported
by water. Mature plants can spawn dozens stems arising from a
single rootstock.
According to the U.S. Fish and Wildlife Service, purple loosestrife
now occurs in every state except Florida, and its highly invasive
nature makes it a threat to some endangered and threatened species.
It is officially regulated as a noxious weed in 19 states. The
New Jersey Department of Agriculture and the Division of Fish
and Wildlife recognize purple loosestrife as an invasive species
of concern, but it is not regulated as a noxious weed by the state.
Purple loosestrife infestations are more common in northern states
and Canada, where glaciation has left an abundance of open wetland
habitat types. A web-search turned up nearly sixty entries dedicated
to the plant's control and eradication. Michigan State University
has enlisted and trained an army of school children to do battle
with the "Purple Monster." Wyoming declares purple loosestrife
the "new enemy." The problem is so serious in Vermont
that the DEC sponsors a "Community Rearing Project"
that trains volunteers to raise loosestrife-eating beetles that
are set loose infested wetlands.
And the "new enemy" has arrived in New Jersey with
infestations reported in the central and northern regions of the
state. In 1997 the NJDEP's Division of Fish and Wildlife Endangered
and Non-Game Species Program asked the Department of Agriculture
(NJDA) for help in controlling heavily infested state-owned lands
where chemical controls were impractical or unsuitable. NJDA's
Division of Plant Industry established a colony of loosestrife
predators in the its Beneficial Insect Laboratory. By the fall
of 1998 NJDA had raised and released over 270,000 adult beetles
in central and northern areas of the state.
Purple loosestrife is beginning to take hold in the Musconetcong
watershed, especially where there are expanses of open wetlands.
The large, shallow dam pools and open wetlands above both the
Saxton Falls and Waterloo Village dams are experiencing a growing
infestation. Some headwater areas above Lake Hopatcong are also
under siege. Further down the valley purple loosestrife is infiltrating
small wetland areas along certain Musconetcong River tributaries.
A particularly conspicuous infestation can be observed along Rt.
57 just above Penwell, where the Beautiful Killer is advancing
yearly in a large marsh along the river. It has even made a recent
appearance on MWA's meadow property across from the Asbury Grist
Mill.
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While biological control is the preferred method for large infestations
of purple loosestrife, small infestations of young purple loosestrife
plants may be pulled by hand. For older plants, spot treating
with a glyphosate type herbicide (Rodeo for wetlands, Roundup
for uplands) may be necessary.
MWA urges residents of the watershed to help control purple loosestrife
by eradicating the plant at the earliest possible stage of infestation.
A great deal of information exists to guide property owners in
helping to not only repel the plant, but protect native wetland
species in the process. The Rutgers Cooperative Extension Service
is just one of many excellent sources of information on the control
and eradication of purple loosestrife.
PURPLE LOOSESTRIFE RESOURCES
Rutgers Extension Service: www.rce.rutgers.edu
Ducks Unlimited Canada: www.ducks.ca
Alien Plant Working Group: www.nps.gov/plants/alien
Cornell University: www.dnr.cornell.edu
