Glenn Nice, Botany and Plant Pathology, Purdue University
This member of the grass family (Poaceae) looks more like bamboo than a grass
(figure 1). It also looks like it should belong in Asia, not in downtown Indianapolis.
You probably have seen this grass in ditches as you drive by or if you have
had a chance to make it up to the Gary or Chicago area you will see copious
amounts along canals and ditches although maybe not quite this big.
Dr. Markus Scholler, Nick Harby, and I (Glenn Nice) went to investigate a report
by Nick of a stand of huge grass in the middle of Indianapolis. What we found
was a stand of very large common reed (Phragmites australis (Cav.) Steud. or
Phragmites communis Trin.) growing in an old canal. Story from property owners
next to the impressive stand stated
that
it had
been there
for many years.
This reed-like grass can have culms anywhere from 5 to 15 feet tall (figure
2). The formation of rhizomes can form large colonies (figure 3) in areas where
water will stand some of the year such as canals and ditches. Blades are lanceolate
and can be 6 to 12 inches or more long, 1/3 to 2 inches wide. Ligules are a
ring of hairs up to 3/10 long (figure 4). Panicles are 6 to 12 inches long
and spikelets are crowded. Seed are wind dispersed giving the seed head a fluffy
look (figure 5).
Once common reed is established it is very difficult to control. Prevention
is the most effective control. This can be aided by reducing land disruption,
pollution through runoff, and erosion.
Once established, cutting and prescribed burning can deplete underground reserves
and eventually control common reed. The cutting or/and burning will have to
be repeated for more than two years.
Some research has reported that a chemical with prescribed burning would promote
other grasses and eventually choke the common reed out. One such suggested
method of chemical control is to cut the grass in the fall (being careful to
collect the seed so not to spread the problems) and immediately applying a
25% solution of glyphosate into the hollow stems. Be sure to select a herbicide
that is labeled for a wetland situation. A permit may be required for application.
Click on the small image to view a larger image.
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Nick Harby and I standing
in the thick of common reed |
Common Reed looking up the stem |
Dense growth of common reed culms |
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The ciliate ligule of common reed |
Common reed seed head |
Downtown Indianapolis within sight |
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