COMMON BUCKTHORN, RHAMNUS CATHARTICA
Common buckthorn is a tree or shrub, which can grow up to 25 feet, although as it is commonly used as a hedge it is usually much shorter. Recently it has been planted in Britain as a hedge plant or ornamental,(although it is a native species) because the common and alder buckthorn are the only food of the Brimstone butterfly, which travels for miles to lay its eggs on this plant.
The genus name of this tree indicates its medicinal uses: rhamnos means “branch” in ancient Greek, and cathartica shows that it was used as a not too drastic purgative. It is a member of the Rhamnaceae family of plants and as such is related to the alder buckthorn and ber fruit (Zizyphus vulgare) though not to sea buckthorn (Hippophae rhamnoides) which belongs to the Eleagnaceae family.
The tree is native to Europe including the British Isles, North Africa and West Asia. It has been introduced into North America, where it is classed as invasive in some states. It has been used as a hedge on both sides of the Atlantic. It was known in Anglo-Saxon times as Highway Thorn and Way thorn, but in Gerard’s time in the 16th century he was calling it Ram’s Thorn and Hart’s Thorn.
The bark and fruit of this tree have a purgative action and have been used as a laxative in the same way as senna and cascara, although it has been discovered that the action is caused by slight damage to the cells lining the walls of the colon, and there was a fear that this could cause permanent damage. The damage causes the colon to contract, so having the laxative effect. The German Commission E still approve the use of buckthorn as a laxative.
It was used as a purgative for children, although this was stopped due to the drastic nature of the herb. For this treatment the juice of the berries was boiled with ginger and pimento with added sugar to make the medicine more palatable.
It made its first appearance in the London Pharmacopoeia in 1650 and was still listed in the British Pharmacopoeia of 1867, but at the turn of that century, it was mainly being used by vets for treating animals. For human consumption the juice of the berries was boiled with aniseed, cardamom, mastica and nutmeg to disguise the taste.