Culver's root
Veronicastrum virginicum (L.) Farw.
other common names: blackroot, Bowman's root, Culver's physic, high veronica, tall speedwall
Veronicastrum: named in honor of St. Veronica
Virginicum: meaning "of Virginia"
Snapdragon family: Scrophilariaceae
Photograph by Thomas Rosburg, Wildflowers of the Tallgrass Prairie: The Upper Midwest, Second Edition