Obedient Plant~ physostegia virginiana, is an ornamental perennial which sometimes may not be considered quite so obedient due to it's invasive tendencies in fertile soil.
Obedient Plant is also known as False Dragonhead due to it's similarity to Snapdragon. It also looks similar to foxglove in my opinion.
Obedient plant is aptly named for a tendency to allow its tiny flowers to be pushed to one side or another and maintain that position for awhile. My kids enjoy this plant, and I've planted my clump near their play area.