This native perennial plant is 1-3' tall and unbranched or sparingly branched. The central stem is 4-angled and covered with long white hairs. The opposite leaves are up to 3½" long and 1½" across. They are ovate or lanceolate-ovate and serrated along the margins. The lower surface of each leaf is more or less pubescent, while the upper surface has scattered appressed hairs. The petioles are about 1" long and covered with spreading hairs. The central stem (and any major side stems) terminates in several whorls of flowers. The whorls of flowers occur above the axils of the upper leaves, or they may occur above pairs of leafy bracts. The flowers in each whorl are densely crowded together. Each flower is up to ½" long, consisting of a tubular calyx with 5 teeth, a 2-lipped corolla, 2 exerted stamens, and a slender style that is divided at its tip. The calyx is light green and exceedingly hairy along the margins of its teeth; the upper teeth are longer than the lower teeth. The corolla is light purple or white and has purple dots on the lower lip; the outer surface of this corolla is pubescent. The lower lip is divided into 3 lobes, while the upper lip functions as a protective hood. The blooming period occurs during the summer and lasts about 1½ months. Each flower is replaced by 4 ovoid nutlets. The root system consists of a taproot.