The genus "Physostegia" native to North America is made up of only three species, but all three grow well in sun or partial shade. The best is "P. virginiana Variegata" with variegated foliage and pink flower spires when it blooms in August.
The common name for "Physostegia" is "False Dragon Head," but it is also known as "Obedient Plant." Of course, obedience is in the eye of the beholder, and I don't believe this plant is obedient in all respects.
It is malleable in a vase as its stems can be bent easily in arrangements. However, it is not obedient about staying where it is planted. If it gets plenty of moisture, which it craves, it will spread aggressively and there will soon be far too much of it.
Disciplining Your Disobedient Plants
There are ways to deal with this. For example, you can plant it a container or plant it in a dry area of the garden where it will be less vigorous. If you have plenty of space you can give it a home of its own so that it can't crowd other plants out. Otherwise you will have to divide it frequently.
While I don't generally like plants that demand this kind of special attention, it blooms at a time when there isn't much else flowering. So, of course I grow it despite its shortcomings.