Physostegia virginiana Obeient Plant or False Dragonhead is a herbaceous perennial plant. Obedient Plant can grow up to 4 feet tall. The flowers are on swivels that can be bent right or left on the stem, giving rise to the common name. The plants bloom in late July to October. Plants spread by way of rhizomes forming large spreading colonies, especially in moisture retentive soils. The flowers are light purple-pink but white flowering plants are not uncommon.