Soapwort, Saponaria officinalis, is a perennial flowering herb, spread by rhizomes, found in the wild but also cultivated for gardens. It is happy in a range of habitats, especially damp woodland and at the water’s edge, but also in hedgerows, road verges and waste ground. The fragrant pink blooms grow in clusters on leafy stems that can grow as tall as 2’ / 60cm.
Although probably originating in western Asia, and therefore not strictly a native British plant, soapwort is known as an ‘archaeophyte’, meaning it was introduced before ‘the modern age’, i.e. before the 16th century AD. It is naturalised as a wild flower across the British Isles, though less commonly in Scotland, and is also naturalised in North America. (There are about twenty different species of soapwort, of which three are found in Britain, including the attractive mat-forming Rock Soapwort, popular with gardeners for alpine beds and rockeries).
Other common names for soapwort in the English-speaking world reflect its membership of the Carnation or Caryophyllaceae plant family: Chimney Pink, Boston Pink, Hedge Pink, Old Maid’s Pink, and so on. The RHS actually lists nearly 30 alternative common names on its website, of which I have subjectively selected a few more: Flop Top, Fuller’s Herb, Lady by the Gate, Sweet Betty, Jill-run-by-the-street, and Devil in a Bush.
We grow soapwort in the Physic Garden for its medicinal history, and because it has a place in our Plants in Industry area.
The botanical name Saponaria derives from the Latin word for soap, saponem, and the plant’s leaves and sap have a distinctly soapy feel. When the plant is steeped in water, it produces a mild cleaning agent, and in some western Asian countries such as Syria, it is still cultivated specifically for its use in cleaning wool. It is also used as such today by conservation organisations, such as English Heritage, for very old, delicate fabrics and those coloured with natural dyestuffs. Helpfully, the plant also contains fungicides, which help to preserve these old materials.
Medicinal Uses
In traditional medicine, soapwort was used in a range of remedies, including as a diuretic, a purgative, for jaundice, and as an expectorant prescribed for coughs and bronchitis.
Nicolas Culpeper also claimed it was an effective cure for venereal diseases, although John Gerard was sceptical about this, ‘until more evident proofes doe convince me’. He did, however, recommend it for healing cuts and wounds.
Modern medical herbalists do not usually recommend its use internally, because of its strongly irritant effect on the gut; although it has been prescribed externally for relief of itchy skin.
Soapwort contains the toxic chemicals saponin and saporin: ingesting the plant can lead to severe vomiting. Some of these toxins are being investigated for their use in targeted cancer treatments; although in early clinical trials, researchers observed a number of adverse reactions including fever, weakness, muscle pain, and bleeding. More research is thus needed into these compounds.
Myth and Magic
Not a myth, but part of local history: soapwort was used to make soap for the woollen mills of Britain, and because of this industrial past it naturalised particularly in locations where the mills once stood: on canal-sides, river banks and so on.
Also not a myth, but seeming as fanciful: Dutch brewers have in the past used the plant to get a good head on their beer.
Acknowledgments – thanks to the following for much of this information
www.wildflowerfinder.org.uk
www.RHS.org.uk
www.ukwildflowers.com
www.wildseed.co.uk
www.drugs.com
www.naturalmedicinalherbs.net
Photo on this page ©RWD – copyright R W Darlington (wildflowerfinder.org.uk)
