This native plant is a member of the vervain family. It can be an annual, biennial or short-lived perennial. In general form the plant resembles the related blue vervain. The leaves are opposite, simple, and toothed. The leaf petioles are up to 2 inches long. The leaves resemble those of nettles (genus Urtica) and give the plant its species name. The stem is rigid and green and covered with long spreading hairs.

The small white flowers bloom along very slender branched spikes. These spikes can be up to 2 feet high, but only a few flowers bloom at any one time. Individual flowers are only 1/8 inch wide. Each consists of a five-lobed corolla and a tubular green calyx with 5 teeth. The white flower color of this species is unusual because most members of the genus have bluish flowers. The plant grows 3-5 feet high and is found in thickets and wood edges in most of the eastern half of North America. It blooms from June to September.  When it grows with proper space, the plant can take the form much like that of blue vervain.

Reproduction of this species is only by seed. Several species of insects feed on the leaves and birds will eat the seeds. The bitter taste deters browsing by deer.