loosestrife is an invasive perennial plant from Eurasia that is primarily
found in wetland areas.
It’s unclear exactly when purple loosestrife first appeared, but
it was first introduced to the eastern North American garden trade in
the early to mid-1800s. This plant may also have been purposely introduced
from Europe for herbal uses or from seeds contained in livestock feed
Purple loosestrife can now be found throughout the United States and southern
Canada. Optimum habitats include freshwater marshes, open stream margins,
and alluvial floodplains. The plant also occurs in wet meadows, river banks, and
edges of ponds and reservoirs. It tolerates fluctuating water levels and
excels in disturbed sites, such as construction sites for docks or marinas.
loosestrife is often associated with cattail, reed canary grass, and other
moist soil plants.
Erect (1-2 m), perennial herb with a square, woody stem and opposite or
whorled leaves. Purple loosestrife flowers from July through August, and
is named for its bright purple flower spikes. One plant may grow as an
individual stalk or as several stalks clumped together.
One loosestrife plant can produce three million seeds annually. The seeds
are long-lived and easily dispersed. Once established each plant is capable
of resprouting from broken stems or roots. Humans have also played their
part in the spread of these invasive plants across North America. Since
the purple loosestrife has such a lovely purple flower a number of folks
have planted them in gardens, and some nursery businesses have even sold
the plant or put its seeds in their wildflower mixes.
2010 Distribution of Purple Loosestrife
loosestrife negatively affects wildlife and agriculture by displacing
and replacing native flora and fauna, and thus eliminating food and
shelter for wildlife.
- By reducing
habitat size, purple loosestrife may have a negative impact on fish
spawning and waterfowl habitats.
agriculture by blocking flow in drainage and irrigation ditches and
decreasing crop yield and quality.
Since 1997 purple loosestrife has been prohibited from sale, transport,
and propagation in Pennsylvania.
control techniques include:
the plant out by the root or burning
of exotic beetles (European Galerucella) that specialize in eating purple
dense stands of purple loosestrife
To read more, view the Pennsylvania Sea Grant Purple loosestrife fact sheet.
FOR MORE INFORMATION ON PURPLE LOOSESTRIFE