1) Herb 
The generic name comes from two Greek words, physa (a bladder) and stege (a covering), referring to the calyx, which becomes full of fruit when mature. Physostegia virginiana is the most common species, and is known as `obedient plant`. University of Texas Herbarium ...
[n] - any of various plants of the genus Physostegia having sessile linear to oblong leaves and showy white or rose or lavender flowers
noun any of various plants of the genus Physostegia having sessile linear to oblong leaves and showy white or rose or lavender flowers