Considering the large size of this plant, its flowers are remarkably small. The scientific name refers to the resemblance of its leaves to those of Urtica spp.
(Nettles). White Vervain resembles two of its relatives, Verbena hastata
(Blue Vervain) and Verbena officinalis
(European Vervain). Blue Vervain has more narrow leaves and its flowers are conspicuously blue, rather than bright white. It is found in sunny wetland habitats more often than White Vervain. European Vervain has small flowers that are white or lavender. It differs from White Vervain primarily by its pinnatifid leaves, which have cleft lobes.