In this new series on Canal-side Flora I’ve chosen a plant that dominated the water’s edge on our recent trip down the South Oxford.
In late Summer the huge umbrella leaves of Butterbur covered the banks, with its enormous leaves large enough: “to kepe a man’s head from raine, and from the heats of the sunne…” according to Herbalist John Gerard (1545 – 1611-12)
The plant commonly referred to as Butterbur or Common Butterbur (Petasites hybridus) and also known by a wonderful array of vernacular descriptive names such as:
Bog Rhubarb, Butter Dock, Pestilence Wort, Devil’s Hat, Bogshorns, Langwort, Umbrella Leaf, Blatterdock, Butterly Bock, Capdockin and Flapperdock.
Butterburs are (surprisingly) members of the daisy family Asteraceae in the genus Petasites which is closely related to the Coltsfoot genus Tussilago (indeed Butterbur is also sometimes referred to as Sweet Coltsfoot).
Butterbur grows in marshy or damp soil, so favours the banks of streams and canals.
Butterbur are generally robust and invasive plants with thick, creeping underground rhizomes and large Rhubarb-like leaves during the growing season. It’s an herbaceous perennial plant.
The flowers are produced in the early spring, before the leaves appear; they are most commonly pale pink, with clusters of flowers on a 5-20 cm stem. The leaves are large, on stout 80–120 cm tall stems, round, with a diameter of 40–70 cm. Butterbur has a distinctive and rather unpleasant aroma.
Several websites claim that the enormous leaves of Butterbur were once used to wrap butter, hence the name ‘Butterbur’.
Butterbur is dioecious, meaning it bears male and female flowers on separate plants. The male plant occurring throughout the UK, but the female plant occurring predominantly in the North and Central UK. The flowers of the male plant are larger (7-12mm) than those of the female plant (3-6mm), but the situation is reverse regarding the height of the plants; the females are taller. It is likely that it is only native where both sexes occur together.
Butterbur has a long history in folk medicine and herblore.
Gerard writes of the Butterbur:
“The roots dried and beaten to powder and drunke in wine is a soveraigne medicine against the plague and pestilent fevers, because it provoketh sweat and driveth from the heart all venim and evill heate; it killeth worms. The powder of the roots cureth all naughty filthy ulcers, if it be strewed therein.”
It was used externally as a poultice to cover ulcerated or wounded skin; in the Middle Ages it was used to treat plague and fevers, and in the 17th Century it was a noted treatment for whooping cough and asthma the modern prescriptive phrase would be “anti-spasmodic”.
Modern studies have been conducted to investigate whether Butterbur could treat other problems, such as migraine headaches and allergic rhinitis as Butterbur was used by Native Americans as a remedy for headache and inflammation. Analysis has indeed shown that some Butterbur species contain the chemicals petasin and isopetasin which are believed to have potential benefits in treating headaches. The highest concentrations occur in Butterbur root. Additionally, a study showed Butterbur extract to be an effective treatment for hay fever without the sedative effect of antihistamine.
However, Butterbur also contains components called pyrrolizidine alkaloids toxic to the liver and may cause cancers. The concentrations are often highest in the rhizomes and stalks, and lowest in the leaves, and may vary depending on where the plants are grown. Current medical advice therefore tends to err on the side of caution and does not recommend the internal use of the unadulterated plant.
On a less serious note Butterbur seeds in some parts of the country have been used for love divination.
‘The seeds of butterdock must be sowed by a young unmarried woman half an hour before sunrise on a Friday morning, in a lonesome place. She must strew the seeds gradually on the grass, saying these words:
I sow, I sow!
Then, my own dear,
Come here, come here,
And mow and mow!
The seed being scattered, she will see her future husband mowing with a scythe at a short distance from her. She must not be frightened, for if she says, “Have mercy on me,” he will immediately vanish! This method is said to be infallible, but it is looked upon as a bold, desperate, and presumptuous undertaking!’ (from Botanical.Com, see full reference below)
By curious coincidence we photographed this heart-shaped hole eaten out of a Butterbur leaf on our journey inland this Summer!
This post was based on information gathered from the following sources: