Vol. 10 Issue 3, Fall 2005
By Nicole Hamilton
Jewelweed is a wonderful plant, both for the medicinal benefits for those of us who react to poison ivy and for the benefit it provides to our hummingbirds as they migrate south in the fall.
Jewelweed (Impatiens capensis) is an annual plant, spreading and repopulating through seeds. Interestingly, the Jewelweed has two types of flowers. One flower is a showy orange flower that is pollinated by bees, wasps, flies and Ruby-throated Hummingbirds, and another that is green and kept closed. This second flower is self-pollinated, giving the plant two means for carrying on its genes.
The orange flower attracts our hummingbirds, serving as a critical food source when other nectar plants from the summer have gone to seed. Each Jewelweed flower produces 2.5 ml of nectar, containing 40% sugar, per day. This nectar and the tiny insects it attracts are critical to the hummingbirds as they work to put on weight. Hummingbirds learn where Jewelweed populations are, and they incorporate these locations into their migration routes and teach them to their young. Planting Jewelweed in your gardens and near feeders is a sure way to enjoy Hummers through the fall.
Jewelweed is also known by the common name “Touch-Me-Not.” This is because the seed pod from the orange flower has a coil inside and when triggered by being touched or disturbed, it explodes, sending the seeds up to four feet from the parent plant. By expelling the seeds, the plant is able to spread to new soil and sun conditions that may be favorable to this new cross-pollinated seed. The seeds produced through self-pollination within the green flower do not have this explosive capability. They are deposited close to the parent, taking advantage of the conditions where the parent plant survived.
Another interesting feature of the Jewelweed plant is that the leaves are unwettable. They have microscopic hairs that trap a very thin layer of air on the surface of the leaf. If you put a leaf into water, it will appear to take on a grayish color because of the trapped air. However, when removed from the water, the leaf will be dry. The purpose for this waterproofing is unknown.
As alluded to earlier, Jewelweed is also a wonderful antidote to poison ivy rash and insect bites. The leaves need to be mashed to allow the juices to come out. This mash is then put on the skin to take away the itching and pain. Fortunately, Jewelweed is often found growing wild near poison ivy, so it can be a quick remedy.