Blue Vervain

This plant not only attracts butterflies and hummingbirds, it has a history.

From tears of Isis to being placed on Jesus's wounds this plant is also called the devil's bane. It was thought to be a cure all and a favorite of witches. Which is probably why Walt Whitman placed it in the realm of  God in Splendor in the Grass:

I see the place of the idea of the Deity incarnated by avatars in human forms;
I see the spots of the successions of priests on the earth—oracles, sacrificers, brahmins, sabians, lamas, monks, muftis, exhorters;
I see where druids walked the groves of Mona—I see the mistletoe and vervain;
I see the temples of the deaths of the bodies of Gods—I see the old signifiers.