By definition, a weed is any plant growing where you don’t want it. To clarify, this holds true only in the garden beds or acreage under your cultivation. “Weeding” flowers in a park planter because they offend your sense of aesthetics is frowned upon.
To a plant, having “weed” embedded right in its name is probably akin to having a “Kick Me” sign on your back. Right out of the box there is bound to be a bit of prejudice against you, fair or unfair. Spotted knapweed, goutweed, and Japanese knotweed are all pernicious invasive species, and deserve all the bad press they get. But occasionally an innocent bystander suffers from this name game.
The native plant commonly known as jewelweed (Impatiens capensis) is one of those exceptions. A succulent plant that thrives in rich moist soils, it is is nearly always welcome no matter where it is found. It’s an annual that is just as happy at the edge of the Arctic Circle as near the equator. Jewelweed has dappled orange, cornucopia-shaped flowers that attract hummingbirds and humans, though not necessarily for the same reason.
Hummingbirds and butterflies have been sipping nectar from its blossoms for who-knows how many millennia. Early settlers began dragging it back to north and central Europe as an ornamental beginning in the 1700s, and native peoples have valued it for thousands of years. Jewelweed may be unique in that it is at once a visual treat, a tactile diversion, and a medicine.
Jewelweed is sometimes called touch-me-not, which might suggest one shouldn’t touch it. On the contrary, it should be handled. Jewelweed is “armed” with projectile seeds, and if you touch a mature seed capsule it will burst with surprising force, strewing seeds in all directions. Touching touch-me-nots is an activity that can amuse children, and some of us who never grew up, for long periods of time.
Poison ivy and jewelweed aren’t friends, but they like the same habitat and seem to have reached a certain rapprochement. Toxic urushiol oil in poison ivy produces dermatitis in most people and a severe allergic reaction in some, but urushiol is neutralized by jewelweed sap. Jewelweed’s thick jointed stem is easily crushed, and you rub this juicy pulp over the skin where poison ivy has contacted it. It helps relieve itchiness caused by insect bites and nettles as well.
Although its reputation as a treatment for poison ivy and other rashes goes back centuries in oral traditions, jewelweed sap has not been well investigated for this purpose in controlled trials. However, the sap has been used to treat athlete’s foot and other fungal conditions, something which does have has a basis in science—research has confirmed jewelweed is anti-fungal.
A close relative of the ornamental impatiens varieties that we love for shady areas, jewelweed is not susceptible to impatiens downy mildew, a disease that has destroyed traditional impatiens in the past few years. Perhaps the key to developing resistant impatiens lies with jewelweed.
Its name may come in part from the way its leaves sparkle when held under water. The leaves are hydrophobic, not wettable, and myriad gemlike air bubbles adhere to them when submerged. It’s possible, too, that it was dubbed a jewel because of its important medicinal uses. Now if we could just get rid of the “weed” portion of its name.
Paul Hetzler is a horticulture and natural resources educator with Cornell Cooperative Extension of St. Lawrence County.