by Barbara Walvoord
If you walk along Bassett Brook Road across the bridge, or if you walk down to the garden on either campus, you’ll see the delicate orange or yellow blossoms of native touch-me-not, also called jewelweed (Impatiens capensis). It like moist conditions, at least partial shade, and acid soil–perfect for Lathrop. Plants can grow up to five feet high, often in dense clumps. The stems are watery and translucent, easily crushed.
Why the name jewelweed? One source says that dew forms on the lips of the flowers, catching the sun like jewels. Another version is that the delicate flowers hang, each from a single thin stem, like jewels. It’s called touch-me-not because the slender green seed pods, which are forming now, will explosively burst open at a touch, spewing tiny seeds in all directions.
These seeds are its only way of reproducing, since jewelweed is an annual. The seeds need “double dormancy”–that is, they have to experience a cold moist period, a warm moist period, then another cold moist period before they sprout. So plants you see now were sown in 2013. People who buy or harvest the seeds for their own gardens sometimes put the seeds in the fridge for 90 days, warm moist place for 90 days, fridge for 90 days, and then plant. This might be one of the only things you really can leave in your fridge for 90 days.
The flowers are well adapted to hummingbird beaks. Bumblebees, butterflies, and other insects help to pollinate the plant. Mice and birds eat the seeds.
Native Americans used the juice of the watery stems to treat poison ivy and stinging nettle. It works because of the binding action of the chemical lawsone. Science has also corroborated the juice’s antifungal properties, and jewelweed has been used to treat athlete’s foot. https://gobotany.newenglandwild.org/species/impatiens/capensis/