A perennial herb, 25-200 cm tall, with quadrangular, poorly ramified, ascending stem. Leaves decussately opposite, ovate or rhombic, 2-9(-12) cm x 1.5-5 cm, cuneate at base, acute or acuminate at apex, serrate, glabrous or minutely pubescent, glandular-punctate; petiole 0.5-2(-4.5) cm long; stipules absent. Inflorescence an opposed cyme arranged in terminal racemes, 7-29 cm long. Flowers pedicellate; calyx 2.5-4.5 mm long (up to 12 mm in fruit), bilabiate, gland-dotted; corolla 10-20 mm long, tubular, bilabiate, white or (pale) lilac; stamens 4, long-protruding from the corolla tube; ovary superior, style long-protruding, slender, with enlarged, club-shaped and shallowly cleft stigma. Fruit splitting into 4 oblong-ovoid nutlets, 1.5-2 mm long, brownish, rugose.

Acts as diuretic (leaves)

PROSEA (Plant Resources of South-East Asia) Foundation

The leaves are used against various kidney complaints and illnesses, renal calculi, phosphaturic catarrh of the bladder, bladder inflammation and renal gravel, gout, and also, in combination with other drugs, to stimulate the kidneys and as a medicine for nephritis, gallstones and diabetes. It is also used as an adjuvant in treatment of bacterial infections of the urinary tract. In mixtures with leaves of other plants it is also used against gout, rheumatism and arteriosclerosis.