Physostegia virginiana (Obedient Plant or False Dragonhead) is an herbaceous perennial that often grows in sandy soil of riverine floodplains and in cracks in rocky substrates. Obedient Plant can grow up to 1.2m (4 feet) tall. It is native to North America, where it is distributed from eastern Canada to northern Mexico. Physostegia are known commonly as obedient plants because a flower pushed to one side will typically stay in that position. The name false dragonhead refers to the dragonheads of the related Dracocephalum.
It is considered a good plant for adding late-season flowers to a garden. Fertile soils produce robust growth and wide spreading, and the plant may require staking. When it grows tall it has a "tendency toward floppiness" that can be controlled with pruning or staking. It can become aggressive in soft, fertile sopils. The flowers are a beautiful shade of lavender-blue and is visually quite delightful.