Monday, June 18, 2012

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