Invasives
Invasives are plants that have come from various locations on the globe. Most introduced
species are not a problem, but a few have found northern Illinois particularly well-
suited and have spread out of control. Without their natural predators and without
some features - particularly fire - that native species are adapted for, these invasives
are able to crowd out our native communities. Like the buckthorn pictured here, they
replace a rich tapestry of life with just a few species, reducing the
variety of birds, mammals and insects that can live in our remaining open spaces.
The following links to the National Park Service information pages on
Weeds Gone Wild provide helpful information
on our common invasive weeds. For example, it's not enough to just cut buckthorn,
an herbicide (such as Roundup or Garlon 4) must be applied to the stumps to prevent regrowth -
except in the spring, when the sap would flush it out. All but leafy spurge are
currently problems at Oak Ridge Marsh, and may be on your property as well. Read more here:
The last one, purple loosestrife, has some similar cousins that are native. It can be
distinguished by its smooth leaves from blue vervain (which has toothed leaves), and
by its downy leaves/upper stem from winged loosestrife (which is smaller and hairless).
