Caryophyllaceae: a straggling, hairless perennial with brittle stems to 1m. found on roadside verges and waste ground, and in damp woodland. The flowers are pink, 25-35mm across, blooming June-August. The leaves are narrowly oval, distinctly veined. Possibly native in a few sites but mainly a naturalised garden escape. Native to Europe, including Britain, from Scandinavia, south and east to Spain and temperate Asia.
Soapwort's main medicinal use is as an expectorant. Its strongly irritant action within the gut is thought to stimulate the cough reflex and increase the production of a more fluid mucus within the respiratory passages. The whole plant, but especially the root, has alterative, antiscrophulatic, cholagogue, depurative, diaphoretic, mildly diuretic, expectorant, purgative, sternutatory and tonic properties.
Seed is best if given a short cold stratification. Sow autumn or late winter in a cold frame. The seed usually germinates within 4 weeks. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in early summer. Succeeds in any moderately fertile well-drained soil in sun or semi-shade, preferring a neutral to alkaline soil. Soapwort should not be grown next to a pond with amphibians or fish in it since if the plant trails into the water it can cause poisoning.