Buchu is the common name for the evergreen Agathosma betulina (previously known as Barosma betulina) in the Rutaceae family. This 2 metre shrub is found in the lower elevation mountains and natural shrub land of the Western Cape in South Africa.
History and mythology
Buchu is a sacred plant to the Khoisan people of Southern Africa, who rubbed the plant on their bodies as an early form of perfume. After the arrival of the Dutch colonists in 1652, the Khoisan introduced them to the useful A. betulina. The plant was then passed on to the Netherlands by the Dutch, who in turn popularised it in early Western medicine. Due to the expensive nature of the plant, only the very rich could afford it so Buchu quickly became known as the ‘Noble’s tea’. The first recorded exportation of Buchu to Britain occurred in 1790, leading to it being included in the British Pharmacopoeia in 1821. Demand for Buchu in the west meant that exportation to Europe and America increased dramatically during that late 1800’s. The popularity of the plant remained high until the 1960’s, when cheaper synthetic substitutes began to replace it. However, in the late 1990s the attraction for all things natural began and resulted in another rise in Buchu use.
Today, Buchu leaves are gathered, dried and exported around the world. However, the demand far exceeds the supply and A. betulina is currently being harvested faster than it can reproduce. In some areas it has even become extinct. To try and combat this, local governments have introduced policies whereby no-one is allowed to neither pick nor buy Buchu without a licence and it can only be harvested every second or third year.
For centuries the locals have used Buchu as a cure for many problems. They mainly used it as an anti-inflammatory agent and diuretic (promoter of urine production) to treat kidney/urinary infections. Locals often took A. betulina in combination with brandy, in a drink aptly named Buchu Brandy.
Though there have been no reported A. betulina poisoning cases, the plant does contain the chemical pulegone. In high doses over an extended period, pulegone can damage the liver, cause kidney irritation and abortions. However, at the therapeutic levels used, this is unlikely to occur.
Over the years more effective, and often synthetic, chemicals have replaced the use of Buchu in western medicine. However, some over-the-counter herbal diuretics still include the plant.
Buchu is the only plant in the world known to have the genetic code to produce diosphenol. This chemical is often used by the food industry to give the flavour and scent of blackcurrants. It has been used to flavour teas, candy and liquors around the world. Diosphenol can also intensify the flavour of other fruit and about 80-85% of Buchu oil exported is used for this purpose. The demand for Buchu oil has become so high that the supply can no longer keep up, resulting in increased harvest and possibly putting the plant at risk of becoming extinct.