Perennial, rhizomatous, and very variable herb, 30–80 cm tall, with ascending, leafy branches that are pubescent to softly pilose. Leaves are sessile, lanceolate to narrowly oblong-elliptic, discolorous and acute, measuring up to 8 cm long and 1.5–3 cm wide. Verticillasters are composed of many flowers arranged in dense terminal and axillary spikes toward the ends of the branches. Calyx is narrowly campanulate, 2–3 mm long and softly hairy. Corolla is lilac, four-lobed and about 4 mm long. Flowers have 4 subequal stamens and subequally bifid style. Fruits are very small, ovoid nutlets, slightly mucilaginous when wet.