P&PDL Picture of the Week for
September 3, 2007

Cut-leaved Teasel

Glenn Nice, Weed Diagnostician, Dept. of Botany & Plant Pathology, Purdue University

You have probably seen common teasel (Dipsacus fullonum), in ditches, waste areas and sometimes in our yards (Figure 1).  Common teasel is a pest in many states, on the noxious weed lists of a few states, and on the Federal Invasive Plant List.  What you may not know is that there is another teasel sneaking in to Indiana under the common teasel disguise.  Cut-leaved teasel (Dipsacus laciniatus) is another teasel that has been found in Indiana, but not in the numbers of common teasel.  Cut-leaved teasel can be distinguished from common teasel by flower color.  Common teasel typically has lilac colored flowers and cut-leaved teasel has almost white or white flowers (Figure 2).  Figure 3 is a picture of the two plants together.  The involcural bracts, the leaves that appear to cradle the egg shaped inflorescence, found in both common and cut-leaved teasel tend to be wider in cut-leaved teasel.  Although if you happen to be looking at one and not the other for comparison it might be difficult to discern which is which unless you have become familiarized with common teasel.

The Indiana Cooperative Agricultural Pest Survey Program is trying to track the occurrence of cut-leaved teasel in the state of Indiana.  If you should happen to see this invasive plant please contact Glenn Nice at (gnice@purdue.edu).  It has presently been found in 5 counties in Indiana (Figure 4).

See cut-leaved teasel on our list of invasive species.

Click image to enlarge

Common teasel

Figure 1

Cutleaf teasel

Figure 2

Common and cutleaf teasel

Figure 3

Map of cutleaf teasel in IN

Figure 4

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service