an erect or ascending herb, annual, sparingly pubescent or nearly glabrous at least below, shining, simple or branched from the base or upwards, 1/3–2 ft. high; stem and branches quadrangular, smooth; upper internodes of the flowering stems and branches exceeding the leaves; leaves mostly opposite, sometimes fasciculate-verticillate, oval, ovate, lanceolate or sublinear, obtuse at the apex, obtuse at the subamplexicaul sessile base or the lower obtusely narrowed and shortly petiolate, toothed, often strongly so, glabrous or somewhat pilose, 1/4–2 in. long, 1/40–1 in. broad; petioles short or obsolete or ranging up to 1/2 in. long; racemes terminating the stem and branches, subcorymbose or elongated, many-flowered, 1–14 in. long; bracts alternate, mostly smaller than the leaves; pedicels slender, mostly pubescent or pilose and 1/4–1 in. long; flowers white and striped with coloured lines outside; calyx-segments oblong or narrowly ovate-oval, obtuse, puberulous, more or less spreading, 1/12– 1/8 in. long in flower, 1/8– 1/6 in. long in fruit; upper corolla-lobes ovate-oblong or oval-oblong, rounded at the apex, 1/6– 1/3 in. long, 1/10– 1/8 in. broad; lower lip rounded, bifid, 1/4– 1/3 in. long; palate bearded, bicallose; spur linear, obtuse, straight, 1/6– 1/5 in. long; filaments white; anthers yellow; capsule obcordate, more or less wedge-shaped at the base, with diverging points or short horns at the outer sides of the curved tops of the valves, 1/4– 3/8 in. long and broad. null