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 2-4 ft tall. The leaves are lanceolate and toothed. The inflorescence is a long, dense raceme containing many tubular pink flowers which resemble snapdragons. The open fruit is shaped like a vase and contains four triangular, 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.