Here you will find information about Woad, Isatis tinctoria, its medicinal and other properties and place in folklore.
A hardy perennial or biennial, this tall striking plant can be grown in most soils and tolerates shade and sun. It may have originated in southern Russia but has naturalised widely from Europe into America and elsewhere, since early times. Because it was once the main source of blue dye in Europe, it was grown extensively as a commercial crop, and may thence have escaped into the wild. The name Isatis is the Greek word for woad, and tinctoria is derived from the Latin tinctura, meaning dye.
A member of the economically important plant family Brassicaceae, woad is related to many other useful, and often edible, plants including mustard, turnip, cabbage, watercress, cauliflower, radish and rapeseed – the latter being a very familiar British commercial crop with the same brilliant yellow flowers. All these plants were originally classified under the family name Cruciferae, meaning cross-bearing, because of the shape of their four-petalled flowers.
Once naturalised, this hardy plant can spread – so prolific is it in the USA that it is there considered an invasive pest. We confine it to the area in our garden that is dedicated to plants found in the Textile Industry, but we admire its colour and architectural value for the garden as a whole, and recognise those medicinal applications that make it suitable for a Physic Garden.
Dyeing
Woad has been cultivated as a dye plant in Europe from the Stone Age, and a dyeing industry was developed in Britain, particularly in East Anglia. Woad was harvested for its leaves, which were crushed into a paste and formed into balls by hand. These balls were dried over a few weeks until hard as wood and then were crumbled into powder, sprinkled with water and left to ferment. When this mixture also dried, it was packed in barrels for the dyers.
The dyers poured hot water over the woad; added potash or urine; and it was again left to ferment for three days before it could be used as a dye bath. The whole process was so smelly that Queen Elizabeth I decreed that it should not be carried out within five miles of any of her palaces.
The plant Indigofera tinctoria grows in India and South East Asia and, as the British Empire spread, it gradually, and more cheaply, replaced woad in the dye vats. With this source of indigo dye readily imported, and with the later Victorian development of synthetic dyes, (which were even cheaper to create), the British woad industry died. The last mill closed in Lincolnshire in 1932.
Woad is not often commercially used nowadays, except by artists and craftspeople interested in working with natural materials. Although it is famously blue, when mixed with dyer’s greenwood (Genista tinctoria) it produces an excellent green. Jenny Dean, a UK spinner, weaver and dyer who uses natural colours has published an article on dyeing with woad, which you can read here.
Medicinal uses
The leaves and roots contain antibacterial and antiviral compounds, useful in a range of ailments. The leaves also contain fever-reducing chemicals.
Nicolas Culpeper stated in his 17th century “herbal” that woad was so drying and astringent it should only be used externally, for treating ulcers and to staunch bleeding. However, in Chinese herbal medicine it is taken internally at quite high doses, and is associated with treatments of a wide range of ailments including mumps, influenza, heat rash and pneumonia. The roots are used to treat cold and throat infections.
An anti-cancer chemical, glucobrassicin, that is found in broccoli, has now been found at twenty times greater quantities in woad, and even more if taken from damaged young leaves. As extraction from broccoli is difficult, woad may prove an effective alternative source.
Warning: never attempt home-medication from plants – always seek professional advice.
Myth and Magic
Woad is associated in British legend with the warpaint of ancient tribesmen, reinforced in recent culture via such films as Braveheart. Warriors rubbed their bodies with woad, to look as strange and fearsome as possible. A Roman writer, Eumenius, described those northern tribes as Picti, meaning ‘painted ones’. Similarly, the old Celtic word Brithon means stained or painted man, and some historians have proposed it as the derivation of the word Britain. The word Woad itself is Germanic in origin, probably introduced to our language by the Anglo-Saxons (who arrived long after those painted warriors).
Woad has also been used in magic and pagan rituals, as an aid in shape-shifting and to assist in looking into the past. It had a reputation as a hallucinogenic, but its main ‘mood altering’ properties are that its raw sap can cause numbness and dizziness in some people.
Another word for woad is Glastum, and some people believe that Glastonbury was ‘the place where woad grows’.
Acknowledgments Thanks to the following for information and opinion:
www.britannica.com
www.thecultureconcept.com
www.thewoadcentre.co.uk
www.fascinatinghistory.blogspot.com
www.woad.org.uk
www.pfaf.org
www.jennydean.co.uk
