A flowering plant consists of a fibrous root. Leaves emersed, petiolate; blade linear-lanceolate to broadly elliptic to ovate, to 30 ´ 1-12 cm. Inflorescences to 1 m. Flowers chasmogamous; sepals 1.7-3.2 mm; petals purplish white to purplish pink, 3.4--6.4 mm, margins ± erose, apex obtuse; anthers ellipsoid, 0.7--1.4 mm; style ± straight, 0.6--1.5 mm, exceeding ovary length. Fruiting heads 4--6.5 mm diam; achenes ovoid, 1.7--3.1 mm, abaxial keels broadly rounded, with 1 median abaxial groove, rarely 2, beak erect or nearly erect.

Antidote, antibacterial, anticholesterolemic, diuretic and hypotensive (root); antibacterial, anticholesterolemic, diaphoretic, diuretic, hypoglycaemic and hypotensive (leaves); astringent (powdered seed).

Common Waterplantain
Plants for a Future

Alismol, alisol-A- monoacetate, asparagine, chrysoeriol, guanidine, lignin, luteolin, nicotinic acid, oleic acid, palmitic acid, pantothenic acid, phenol, pyridoxine, stearic acid, tannin (plant); alisol-A, beta-sitosterol, choline, lecithin, valine (rhizome); rutin (leaf)

Helps to treat renal calculus, cystitis, dysentery and epilepsy (dried leaves); for hydrophobia, to lower blood pressure, cholesterol, blood sugar levels, oliguria, oedema, nephritis, acute diarrhoea and fatty liver (roots); for leprosy, to bruises and swellings (fresh leaves); to promote conception (whole plant).

Doses 20–40 times higher than clinical dose is hepatotoxic and nephrotoxic in rats. Rhizome, (as a diuretic), should not be used when there is a clear, thin vaginal discharge since it may cause more than usual excretion of sodium and urea in normal healthy subjects.