Physostegia virginiana

Physostegia virginiana, the obedient plant, obedience or false dragonhead, is a species of flowering plant in the mint family, Lamiaceae. 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 often stay in that position. The name “false dragonhead” refers to the dragonheads of the related "Dracocephalum", a genus to which the plant once belonged.
Description.
It is a rhizomatous herbaceous perennial producing clumps of stiff, squared stems tall. The leaves are lanceolate and toothed. The inflorescence is a long, dense raceme containing many tubular pink flowers which resemble snapdragons. The fruit is a capsule containing many round, black seeds.
Taxonomy.
There are two recognized subspecies. They are:
Cultivars of "P. virginiana" often do not fit well into either of the two varieties and are intermediate in characters. They are thought to have originated from hybridization between the two subspecies.
Cultivation.
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. It can be aggressive and dominate a landscape.
Cultivars.
Several cultivars have been bred for color variety. Some () have earned the Royal Horticultural Society's Award of Garden Merit.
Cultivars include.