Teasel takes over where wildflowers grow

It stands tall and prickly, bearing seed heads that dare you to get close. Where there’s one, there are legions. They are well-armed and on the offense.

The plant is teasel, a species that hitched a ride across the Atlantic from Europe in the early 19th century. It quickly made itself at home in the east and traveled west by attaching its spiny seeds to the coats of animals, the feed bags of horses, and people’s clothing.

Fast forward to the present, and teasel is still spread inadvertently — now by mowers along highways. Thus this European visitor has traveled across North America, and it’s here to stay.

Teasel has a checkered history. It’s high on the botanical hit list today, but it earned its keep as a multiuse plant in the 19th century. As with many European imports, it was considered a familiar friend from back home until it wore out its welcome in the recent past.

The etymologies of both its scientific and common names reveal its uses. Consider first the scientific name for the genus, Dispacus. This comes from a Greek word for thirst, referring to the fact that rainwater collects in the leaf bases along the stem. This water may have quenched the thirst of insects and birds, but for people this water held medicinal value.

According to the website Wild about Wildflowers (www.wildaboutwildflowers.co.uk), the water collected in teasel was widely used in the Old World for skin-related ailments. It was a topical cleanser for dermatitis, acne, and warts. A poultice made from teasel was applied to wounds and used to reduce eye inflammation. A decoction of the plant was a hopeful treatment for tuberculosis patients.

The common names indicate yet more uses of this prickly plant. Known as agueweed, feverwort and sweating plant, it clearly played a role in fighting fevers. Crosswort, Indian sage, and thoroughwort imply a variety of other medicinal uses.

The name teasel is derived from an Old English verb meaning “to tease.” The bristly seed heads were used in teasing, or carding, the nap of wool.

“These heads are fixed on the rim of a wheel, or on a cylinder, which is made to revolve against the surface of the cloth,” wrote Maude Grieve in her 1931 publication “Modern Herbal.” Even as late as the 1930s there was no better way to work fabric. Grieve claimed that the “combined rigidity and elasticity” made teasel the number one choice in the fabric industry for carding.

Another plus for the plant is that it contains the biochemical compound indigotin and produces a beautiful blue dye, making it all the more popular in fabric making. And yet another artistic use of teasel is in flower arranging.

Sounds like a great plant, eh? If only it weren’t such a big botanical bully. Where teasel grows, all other plants — native or nonnative, wild or cultivated — are displaced.

“Teasel is so aggressive,” according to Greg Gremaud and Tim Smith of the Missouri Department of Conservation, “that it can invade, out-compete and displace even a thick fescue stand.”

Plant ecologist Ben Haberthur with the Forest Preserve District of Kane County considers teasel a “prickly pest” in natural areas.

“Both Cut-Leaved Teasel (Dipsacus laciniatus), and to a lesser extent, its cousin Common Teasel (Dipsacus fullonum) wreak havoc in the natural areas across (Kane County).”

Like many invasive weeds, teasel is extra talented at reproduction. Seed heads mature quickly and can produce more than 2,000 seeds from midsummer well into fall. Not only is the sheer number of seeds a daunting challenge, so is the fact that they are viable for two years and up to 80 percent of these may germinate.

“This trait leads to the formation of dense monotypic stands of teasel at the exclusion of nearly every other plant species in the area,” commented Haberthur.

Controlling the indomitable advance of teasel requires more than a little weed-pulling.

“We use an integrated vegetation management approach,” said Haberthur, “which incorporates various control techniques and repeated monitoring of treatment efficacy.”

For all its useful traits and all the ecological challenges it brings, teasel has both friends and foe. There is no doubt that this tall spiky plant from Europe has played a prominent role in our cultural history and has an impact on today’s ecology as well.

Ÿ Valerie Blaine is a naturalist with the Forest Preserve District of Kane County. You can reach her at blainevalerie@kaneforest.com.