This native perennial plant is 2-3½' tall, branching occasionally near the apex. The four-angled stems are light green and glabrous to finely pubescent. The opposite leaves are up to 4' long and 2' across, and they have short petioles. The leaves are cordate to broadly lanceolate in shape and their margins are crenate to crenate-serrate. The upper surface of the leaves is conspicuously veined and dull green, while the lower surface is white and finely canescent. The foliage has an anise scent. The upper stems terminate in spikes of flowers about 3-6' long. The small flowers are arranged in dense whorls that are crowded along the spike, although sometimes the whorls are less crowded and more interrupted. The calyx of a flower is tubular and has five teeth; it is usually dull blue-violet or a similar color, becoming more colorful toward its tips. The tubular flowers are about 1/3' long, extending beyond the calyx. They are blue-violet. The corolla of a flower is divided into a short upper lip and a longer lower lip. The lower lip has 2 small lateral lobes and a larger central lobe. Exerted from the throat of the flower are 4 stamens with blue-violet anthers, and a style that is cleft toward its tip. The flowers bloom in scattered locations along the spikes for about 1-2 months from mid- to late summer. During this time, calyx of each flower remains somewhat colorful. There is no floral scent. The flowers are replaced by nutlets that are oval-shaped and smooth. The root system produces a taproot.