You may have noticed this lovely flower growing in large patches along the edges of rivers and streams and in ditches and woodland areas around Ottawa. Its name is Dame’s Rocket or Dame’s violet (Hesperis matronalis).
Although it is certainly lovely to look at, Dame’s Rocket is considered an invasive species in Canada. It was brought over from Europe a long time ago as an ornamental plant for gardens but has since escaped cultivation and infiltrated our ecosystems where it out competes native wildflowers for resources and space.
For a full list of all the herbaceous plants that are considered invasive species go to the Canadian Botanical Conservation Network’s website.