Vervain has one of those plants of Venus aspects. It teaches us that plants have many layers of energy. They surely do. Every herbalist knows what I mean when I say this: Vervain has a relation to birds as does the planet Venus. Pigeons were considered by the Greeks to feed on vervain.
It is also noteworthy that the Venus herbs can treat the skin. This is vervain's specialty. In ancient times, this herb was used to treat tuberculosis. I find this herb very effective for many disorders.
I find that most herbs have some allure to magic. It is suggested to pick vervain before sunrise on the first day of the New Moon.
Read about all these herbs in The Witching Herbs by Harold Roth.