Perennial with erect, branched, leafy stems up to 80 cm, ± glabrous or with a sparse eglandular indumentum. Leaves 3-8 x 1.5-4 cm, ovate-elliptic; petioles 10-15 mm. Inflorescence an oblong terminal spike c. 50-70 x 15 mm, with the lower verticillaster distant, approximately above. Calyx 3-4 mm, tubular, ribbed; teeth ± subulate. Corolla lilac. Sterile.