Annual, usually slender. Stems erect, ascending or prostrate often branched from the base, 10-40 cm, almost glabrous or with a sparse indumentum of short usually retrorse eglandular hairs, purplish below or not, with few leaves. Leaves broadly ovate to reniform, c. 10-20 x 10-20 mm, crenate to lobed, obtuse, rounded or cordate at base, pubescent; petiole of basal leaves 10-20 cm. Verticillasters 1-5, distant, up to 16-flowered, almost hidden by enclosing amplexicaul leaves. Bracts present or absent. Calyx 4-7 mm narrow tubular, ± densely pubescent with eglandular hairs; teeth narrow triangular, acuminate, about as long as tube, equal, converging in fruit. Corolla purple-pink, 15-20 mm; upper lip pubescent to vinous, straight; lower lip reflexed, shorter than upper; tube slender, straight, c. 0.8 mm in width, exannulate. Stamens included under corolla upper lip. Nutlets c. 2-2.5 x 1-1.5 mm, smooth, with a short broad-based stipe, dearly trigonous below, brown, apically rounded, usually with numerous white raised blotches, not mucilaginous on wetting.