Obedient Plant, Physostegia virginiana
In the mint family, the obedient plant gets its name from the ability of the flowers on the stalk to be twisted into any position, where they will remain. It can be agressive in rich, moist soils, so gardeners should divide clumps every year or so to keep plants contained, and pull out plants invading other parts of the garden. A great choice for a meadow or native garden as it is visited by bees, hummingbirds and other pollinators.
The flowers are 1" pale purple to rose, borne on a showy terminal spike. The corolla is swollen at the throat, the upper lip is domed, the lower lip is spreading and has three lobes. Its stems may flop in rich soils, shade or hot temperatures, making staking of taller plants necessary. Each spike of flowers bloom starting at the bottom and working their way up the spike to the top.
Obedient plants grow best in moist, well-drained, moderately fertile soil and sun to part sun. In the wild, they can be found in wet meadows, barrens and glades, seepages in open woods, damp thickets, among other sites. It does grow in open upland forests as long as the soil is quite high in pH. Uncommon to infrequent in the NC mountains. They can be propagated by seed or by the division of roots in the spring.
The tree frog is resting on a Liatris plant and peeking around the Obedient plant. Photo by K. Mulcahy
Sources:https://plants.ces.ncsu.edu/plants, https://www.wildflower.org/plants/result.php?id_plant=caam2, other authoritative resources and personal experience.