White Vervain, a native species, has been added to the USWildflowers database (02/11/2013.) Scientific name is Verbena urticifolia.  It  is also known by the common name Nettle-leaf Verbena .  Photo below was taken in Walker County, GA , on Jul 29, 2011.   Go to the White Vervain detail page for more photos and information.

White Vervain, Nettle-leaf Verbena – Verbena urticifolia