"Annual; stem to 1.22 m high, much branched, acutely 4-angular, shallowly furrowed, the angles pustular with tubercles tipped by caducous bristles, the nodes annulate with very small hairs, otherwise glabrous. Leaves broadly ovate to oval-rhomboid, 2.6-7.5 x 2-4.3 cm, truncate to cuneate at base, acuminate, irregularly crenate-serrate, thin, membranous, scaberulous above, glabrous beneath; petioles 1.7-5 cm. Racemes linear, 5-6 cm long; verticils often 6-flowered. Floral leaves obspathulate to oval-oblong, 1 mm long, aristate. Pedicels 1 mm long, hispidulous. Calyx 1.75-2 mm long, longer in fruit; tube subventricose, 1.25 mm long, hispidulous with gland tipped hairs at base without, somewhat inflated at base in front; upper lip broadly ovate, 0.75 x 1 mm, acuminate; lower lip as long as upper, 4-dentate, the lateral ones triangular-ovate, the anterior ones triangular-lanceolate, acuminate, aristate. Corolla 2.5-3 mm long, mauvish-pink; tube straight, campanulate, 1.75 mm long, glabrous without, thinly pubescent within; upper lip erect, 3-lobed, lobes rounded, central one 2-fid; lower lip slightly longer, oval-oblong, flat, hispidulous ventrally. Stamens didymous, included; anterior filaments longer than posterior all glabrous; anthers 2-celled, the cells continuous. Style glabrous, shortly 2-fid at apex; branches oblong-oval. Nutlets broadly ellipsoid, 0.8 mm long, compressed, dark brown."
Aromatic annual herb up to c. 1 m tall. Stems erect, strongly 4-angled, branching above, more or less hairless or with short appressed hairs on the inflorescence axis. Leaves opposite, ovate, up to 5 × 2(3) cm, glandular-punctate, usually hairless or rarely with scattered appressed hairs; margin serrate; petiole 10-35 mm long. Inflorescences mainly axillary with many, usually 6-flowered verticils 3-5 mm apart; flowers often concentrated on one side of the inflorescence. Calyx 1-1.5 mm long with scattered sessile glands and short hairs. Corolla white, blue or purple, 2-3 mm long; tube straight; lips with scattered glands.