A softly woolly or subsilky perennial herb; rootstock stout woody; stem bluntly 4-angled, clothed with erect hairs; leaves opposite, ovate, obtuse or acute at apex, rounded or cuneate at base, crenate, thick, softly tomentose or silky, subsessile below, gradually becoming sessile upwards; verticillaster axillary, dense, many flowered; bracts half as long as the calyx, setaceous, densely hairy or ciliate; calyx tubular, campanulate, oblique, upper half of tube villous inside, mouth truncate, teeth minute, triangular-subulate, alternately shorter, deltoid-subulate; corolla white, tube as long as the calyx, annulate above the middle, upper lip densely silky on both sides, midlobe of lower lip very large, obovate; stamens-4, didynamous included in the upper lip of corolla, filaments glabrous, anther 2-celled, connivent; disc entire, glandular; ovary 4-partite, style subulate at the apex, posterior lobe obsolete; nutlets-4,very small, obtuse, dry, basal scar small.