Dame's Rocket is one of those beautiful plants that is alien and somewhat invasive. By invasive, I mean that it is found in great, colorful clumps in ditches along roadsides, an area that is pretty much only populated by alien invasives. So, it apparently out-competes other invasives.
Colors vary from white to pink to lavender to purple
It is a pretty flower
It has the typical pods of plants in the Mustard family - Brassicaceae