The genus Physostegia is a group of perennial plants and is part of the Lamiaceae family.
They are perennial herbs up to 6 feet high, usually arising from rhizomes.
The generic name comes from two Greek words, physa (a bladder) and stege (a covering), which refers to the calyx, which becomes full of fruit when mature.
It is suggested that it is a wholly North American genus of 12 species. Physostegia virginiana is the most common of these species, and is known as "Obedient Plant." Species in this genus include: