Black root (Veronicastrum virginicum), also known as Culver's root, has a history of use in traditional North American herbal medicine, particularly among Native American groups and early European settlers. It was primarily valued as a bitter tonic, laxative, and cholagogue (promoting bile flow). Some historical sources mention its occasional use for conditions involving the liver, gallbladder, and digestive tract. There are anecdotal reports and folk traditions describing its use for "dropsy" (an archaic term for edema, sometimes associated with kidney disease), but direct evidence for its use in treating or supporting kidney infections (pyelonephritis) is scant. No robust clinical or pharmacological studies exist validating its efficacy or safety for kidney infections specifically. Most traditional references to black root focus on its purgative and liver-supporting properties, not on renal or urinary tract infections. Contemporary herbalists rarely recommend black root for kidney infections, and it is not included in authoritative herbal pharmacopoeias for this indication. Thus, its use for kidney infection is primarily rooted in sparse traditional practices rather than scientific evidence, and the strength of evidence for this application is very weak.