Be on the Lookout - Teasel

Cutleaf teasel flower

Occasionally, we will place a post up on this blog about a particular invasive species.  These 'Be on the Lookout' posts are timed to when the target species is most visible and easily identified.  Today's post is on Teasel.

Southern Illinois is home to two species of exotic teasels.  Common teasel (Dipsacus fullonum) and cutleaf teasel (D. laciniatus).  Both teasel species can be found in grasslands, pasture, and roadsides.  These thistle-like species are very spiny and can form dense stands if left uncontrolled. 

Early summer is the perfect time of year to identify teasel as the second-year plants are starting to flower.  Teasel is a biennial plant, with first-year plants being small rosettes and a large flowering stalk on the second-year plants.  Look for purple (common) or white (cutleaf) flowers on a 3-7 feet tall flowering stalks.  The flower-heads are very unique, looking like a spiny dome with rings of small flowers along the outside and long bracts surrounding it. 

To learn more about teasel and other invasive plants, see the 'Species of Concern' page of the River to River CWMA's website at:  http://www.rtrcwma.org/species.html

Start looking for Japanese Stiltgrass



Early Summer Stiltgrass Infestation

 Now that garlic mustard season is slowing down and turkey and morel hunting has came to an end, it is time for landowners to start looking for Japanese stiltgrass.  This relatively new species may not be on many landowner's radar yet.  While it has been in southern Illinois since the late 1960s, only in the last 15 or so years has it really started to spread wide.  The recent ice and wind storms we've had is only helping this plant take hold in our forests.

Japanese stiltgrass is a serious invader of bottomland and other moist woodlands but can also grow in drier areas.  Keep an eye out for this plant starting to invade along roads, trails, deer paths, streamsides, and fire breaks.  This is an annual plant that produces a lot of seed, so it is important to find and control it before it flowers and reproduces for the year (usually late August to early September). 

Look for patches of a wiry grass with short, wide leaves.  More information on Japanse stiltgrass, including identification tips and control recommendations can be found on the River to River CWMA's 'Species of Concern' page:  http://www.rtrcwma.org/species.html.

Also, the River to River CWMA organized a conference on Japanese Stiltgrass in 2010 and all of the presentations, along with a summary white paper, are available at: http://www.rtrcwma.org/stiltgrass/.

Be on the Lookout - Oriental Bittersweet

This is the time of year that people start thinking about decorative wreaths. Although the fact in unknown to most, these holiday wreaths can harbor an invasive species. Oriental bittersweet (Celastrus orbiculatus) is a very aggressive invasive vine that invades forests and forest edges across the eastern United States. It is very prevalent in Southern Illinois. Oriental bittersweet is a popular vine for making wreaths because of its showy red berries and bendable vines. However, when you discard that wreath in the spring, you could actually be planting bittersweet on your land. Learn to recognize bittersweet and other invasive species by visiting the River to River CWMA website at:
http://www.rtrcwma.org/species.html.

Also, here is a link to a article Oriental bittersweet and wreaths:
http://concord.patch.com/articles/pretty-perilous-plant

Be on the Lookout - Bush Honeysuckle

Bush Honeysuckle, Lonicera maackii, is an extremely aggressive invasive shrub in our region. Fall is the best time to identify it because it often stays green when our native shrubs and sapligs loose there leaves.  In fact, you can often identify bush honeysuckle easily in late fall after most of other species have dropped their leaves by simply driving downt he road and looking for color within the woods. In the fall, honeysuckle also has bright red berries. If you think you have a honeysuckle plant, look for the red berries, opposite leaves with pointed tips, and light tan stringy bark. This is a plant that you do not want to leave alone. As soon as you identify this as being on your land, you should start controlling it. Waiting even a year can result in a drastic increase in its population size.

Be on the Lookout - Purple Loosestrife

Purple loosestrife is an invader of wetland and riparian habitats.  Its tall spike of purple flowers makes it an easily recognizable plant.  Some purple loosestrife has been indentified within the CWMA region, but we are always looking for more reports.  Mid-tolate summer is the best time to identify purple loosestrife because the flowers are present.  If you out in a boat this summer keep a lookout for this invasive plant and be sure to report any suspected infestations to us at www.rtrcwma.org/report/.  For more information on purple loosestrife see: http://www.invasive.org/weedus/subject.html?sub=3047.

Be on the Lookout - Spotted Knapweed

Catherine Herms, bugwood.org

Spotted Knapweed, an invasive plant most commonly associated with invading range lands in the western United States, has been reported from 4 counties within the River to River CWMA.  Spotted Knapweed is an invader of open and disturbed lands and can out-compete and displace other species.  It is flowering this time of year and is easily recognizable.  To find out how to identify this plant or more about its ecology, go to http://www.invasive.org/species%20subject.cfm?sub=3013. The River to River CWMA is interested in recording any newly found infestations of this plant.    If you find a suspected location, please submit a report along with digital images to the CMWA through our report form: Report