Clearwood (Pilea pumila)

By Michael Leach

Without a bit of fanfare, at least one North American native plant is retaking ground covered by that odious invader — garlic mustard.

Clearweed, Pilea pumila, which grows throughout the eastern two-thirds of the U.S., has evolved resistance to garlic mustard and is striking back. Garlic mustard succeeds so well because it produces sinigrin, a chemical that kills fungi needed by native plants to extract nutrients from the soil. This chemical warfare gives garlic mustard an enormous advantage.

Garlic mustard

I learned about this encouraging development from a periodic news wrap up from the Garden Writers Association. A story about the University of Georgia study appears in the American Nurseryman http://www.amerinursery.com/blog-2957.aspx.

The article quotes Richard Lankau, the study’s author: “The implications of this study are encouraging because they show that the native plants aren’t taking this invasion lying down.” He adds, “If you were to take a longer view … exotic species could become integrated into their communities in a way that is less problematic for the natives.”

Only time will tell.

Meanwhile, it turns out some native plants are take-over thugs, too. In a recent Ohio State University Extension newsletter I read about the enchantingly beautiful American lotus. I saw some flowering along a Virginia roadside recently and was instantly captivated.

The native lotus is listed as “threatened” in Michigan and “endangered” in Pennsylvania and New Jersey — but it’s banned in Connecticut and included on the state’s invasive plant list.

Go figure. Nothing is 100 percent when it comes to plants.