Double, double toil and trouble;
Fire burn and caldron bubble.
Fillet of a fenny snake,
In the caldron boil and bake;

Eye of newt and toe of frog,
Wool of bat and tongue of dog,
Adder’s fork and blind-worm’s sting,
Lizard’s leg and howlet’s wing,

Well, where on earth would you get a newt eye or a dog’s tongue from? This poem by William Shakespeare appeared in his play, ‘Macbeth’ and explores themes such as fate, evil, and the supernatural.

Many references in the witches’ song allude to plants known for their healing properties. In the past, herbalists were often suspected of witchcraft and used coded language to describe their plants, keeping their true names secret to avoid persecution.

Newts are fascinating creatures, known for their unique ability to regenerate lost limbs. These small amphibians, often found in wetlands, have long captured human imagination. In folklore and ancient practices, newts were associated with magic and mystery, making them a symbol of transformation and healing.

The ‘eye of newt’ mentioned in the witches’ song is more than just a creepy ingredient, they were thought to be a reference to mustard seeds. In folklore, mustard seeds were believed to offer protection and were sometimes scattered around a home to ward off evil spirits.

In Christian tradition, the mustard seed symbolises faith and growth, as referenced in the Bible where Jesus says, “The kingdom of heaven is like a mustard seed, which a man took and planted in his field”.

Scientifically, mustard seeds have been used in poultices and compresses to relieve pain and reduce inflammation, particularly in conditions like arthritis and muscle pain and The Journal of Dermatology released positive findings in 2019 on the effects of mustard seeds in reducing the inflammation associated with psoriasis.

Symbolically, the ‘tongue of dog’ may have represented the idea of speech, communication, or even betrayal in the witches’ song. Dogs are often seen as loyal and protective and, possibly, it was in reference to the real plant known as hound’s-tongue (Cynoglossum officinale), known for its soft, hairy leaves that resemble a dog’s tongue.

A member of the same family as borage, hound’s-tongue, is a medicinal plant whose roots are used for their astringent and healing properties and for their sedative, calming, and slightly narcotic effects. This species, originating from Europe where it grows wild in mountainous fields, is cultivated only for its medicinal properties. 

According to the Plant Disease Journal, this plant also hosts a specific virus and contains pyrrolizidine alkaloids, which are toxic to grazing animals – making it an ideal ingredient for a witchy brew.

Taken literally, ‘wool of bat’ might refer to the fine, soft hair or fur found on certain species of bats. While bats don’t have wool in the traditional sense, their fur could be described as wool-like. Bats, being nocturnal and often associated with darkness and mystery, add to the eerie and supernatural atmosphere of the witches’ spell.

Some suggest ‘wool of bat’ could refer to mosses, lichens, or other plants with a soft, woolly texture such as the lichen which grows on trees known as old man’s beard which is part of the family called Usnea.

While Usnea has a long history of use, scientific validation and standardisation of this plant is being researched for its application in modern medicine. Researchers are exploring how Usnea’s antimicrobial properties can be harnessed alongside or as alternatives to synthetic antibiotics.

From the grotesque to the magnificent, and even the scientific, plants have accompanied humanity through the ages, enriching our lives in countless ways. Their roles have evolved from mystical symbols in ancient rituals to sources of cutting-edge medicines and sustainable solutions.