All in the Family - Invasive Impatiens
This week’s post is on two plants – in the same genus - Impatiens. Something less dramatic than Giant Hogweed, but certainly more widespread. Charlottetown especially is full of this pair – Small-flowered Impatiens, Impatiens parviflora (Small Balsam or Small-flowered Touch-me-not) and Himalayan Balsam –Impatiens glandulifera, also called Policeman's Helmet, Bobby Tops, Copper Tops, and Gnome's Hatstand and Kiss-me-on-the-mountain. As so many plants do, these ones have many English names. Even their scientific name implies their form.
The Touch-me-not part of their name comes from the seed pods that, when ripe, will pop open in a weird way, when touched. The pods seem to become a living slightly squirmy thing in your hand when they spring open. It is an odd sensation!
On the small-flowered impatiens you will find tiny yellow flowers similar to our native Jewel Weed (also Spotted Touch-me-not) found growing abundantly on river and stream sides. Large magenta flowers grow on the Himalayan balsam. Members of the Impatiens genus have thin skinned stalks that appear almost translucent and have plenty of sap or juice in those stems. This plant has been used to reduce the sting and itch of poison ivy and stinging nettle.
Not sure if you have seen these plants? Take a walk down Kent Street between Queen and Pownal Streets and you will see the small-flowered version in nearly every front garden. There is plenty in Victoria Park too. Look to wet areas next to streams beside the forestry offices on Beach Grove Road, along the trails in Memorial Park near Beach Grove Home.
How can such a plant be invasive or harmful? It can take over large areas out-competing and shading out smaller native plants and reducing bio-diversity. Himalayan Balsam grows so profusely in shade and in sun. It can choke small waterways, blocking streams and springs. Its weak root systems can also cause increases in soil erosion. Fortunately, these plants are fairly easy to control before they get too widespread – just pull them out before they go to seed for two or three years, or until the population is gone.
PEI Invasive Species Council has fact sheets on Himalayan Balsam for both identification and for management - check under our Resource page!
- Jackie Waddell. PEIISC Member