A much-branched, clump-forming perennial, pleasantly scented, with square stems. Flowers normally in 1 terminal cluster, subtended by many small leaves, which frequently are rose-purple. Floral tubes to 1½ inches long, ending in 2 lips, the lower broad and recurving, the upper arching upward with stamens protruding, lavender, lilac, or rose. The subtending bracts are pale green or lilac-tinged. Blooms May–August. Leaves opposite, on definitive stalks, gray-green, with fine hairs, ovate-lanceolate, with small teeth.
Similar species: Beebalm (M. bradburiana) is quite similar, but its leaves are stemless.