Annual, rather slender, pleasingly aromatic. Stems usually branched, erect, 15-80 cm, quadrangular, with few very short retrorse hairs mainly on angles of stem, leafy. Leaves ovate, 25-35 x 15-20 mm, regularly serrate, acute, cuneate, glabrous or with a sparse indumentum of very short eglandular hairs, gland-dotted; petiole on lower leaves c. 15 mm, less above. Inflorescence unbranched to much branched. Verticillasters 5-15, each with 2 often secund flowers. Bracts narrow oblong-elliptic, 2-3 mm, as long as the pedicels. Calyx in flower c. 1.5 mm, soon in fruit expanding to 5-5.5 mm with two lower lobes longer than the campanulate tube and a subentire-truncate shortly 3-toothed upper lip, 10-nerved; indumentum of short pilose hairs, glabrescent, gland dotted; throat villous. Corolla purplish or white marked pink or purple, inconspicuous, soon deciduous, c. 2-2.5 mm, upper and lower lobes weakly differentiated. Stamens 2; thecae divergent. Nutlets brown, almost globose, c. 1.2 x 1.2 mm, with a prominent raised reticulum.