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Life Cycle: |
Rhizomatous perennial |
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Germinates: |
Spring |
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Flowers: |
July-October |
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Seeds Mature: |
Seeds stay in capsules that persist
on plant stalks through the winter |
History/Origin
This
native of Europe and Asia was first introduced in the early 1800's
and most likely spread through the American interior by river-born
traffic. The flower was purposefully brought into the Intermountain
West as an ornamental for
flowerbeds.
Biology/Ecology
Purple
loosestrife likes to have its feet wet. Seeds of this plant are
spread by water and on the feet and bodies of birds and wetland
animals. Seeds will often sink in the water, but upon germination
the new seedlings float to the surface and take root where possible.
These seeds usually germinate
in such high densities that they suppress native plant seedlings.
After flowering the standing plant stalks die leaving only the woody
roots alive. These dead seasonal stalks can remain standing for
two years. New seasonal growth sprouts up among the dead stalks,
from both the root crown and along rhizomes,
creating a densely grown stand of living and dead stalks.
Known Impacts
Detrimental:
The
dense stand of plant roots and stalks, impedes water flow and can
clog irrigation canals and wetland channels, reducing the amount
of open water for waterfowl. These same stands often crowd out over
50% of the native vegetation. Desired plants such as cattails and
bullrush are overrun, creating a shift in wildlife habitats that
affects predator/prey relationships, eliminates nesting sites, and
generally reduces vertebrate and invertebrate populations.
Beneficial:
The
flowers of this plant are beautiful and are often used in ornamental
flower beds. It was also used as a medicinal
herb by early settlers of America.
Potential Locations
Purple
Loosestrife often grows in association with cattails and other wetland
plants. These areas include streams, canals, ditches, shorelines
of shallow ponds, and many other areas with moist soil.
Control/Management
• Herbicides are the best know tool for removing this plant(example
herbicide: Escort, Roundup Ultra, Arsenal, Velpar [look
at herbicide label: free search]).
• Education should be a top priority. If it is considered just another
pretty "wildflower" people will not act or even understand the need
for control measures.
• Present bio-control
agents can slow down the spread, but do not eradicate the weed.
• Hand pulling or other physical manipulation has little or no effect
because of the rhizomes.
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