The botanical name of Marula is Sclerocarya birrea, and is a single-stemmed tree with a wide-spreading, round crown and characteristic grey, mottled bark, peeling in disc-shaped flakes. It is a tall, deciduous tree (15-20m high). The compound leaves are grey-green in color, but turn pale yellow prior to being shed. Denuded of leaves, the top branches appear abnormally thick and erect, like upturned fingers (digitaliform). The tree remains bare for several months of the year.
It is best known for its golf ball-sized fruit, which it bears in profusion during summer. They are round to oval, green when young, and becoming butter-yellow as they ripen. The thick, soft, leathery exocarp encloses a white, slimy fruit pulp and a large, hard, woody stone. The seeds contained therein are white and nut-like.
The Marula tree is common in the lower-lying areas of Southern Africa, and is found, in abundance, in Namibia, Botswana, Zambia and Zimbabwe.
Use of the Marula tree
The bark, which is 10-20% tannin, contains procyanidins, which have been linked to its anti-diarrhoea activity, while the plant is said to contain gallotannins, flavonoids and catechins. It is claimed that the leaves have hypoglycaemic effects.
The astringent bark has a range of medicinal uses, including as treatments for diarrhoea, diabetes, fever and malaria. It also plays a prominent role in many traditional cultures in Southern Africa. Some believe that the sex of a child can be pre-determined by administering an infusion of the bark of a male or female tree to a pregnant woman. The Zulu and Tonga peoples both call Marula the ‘marriage tree’, and a brew of the bark is administered as part of a cleansing ritual prior to marriage.
The fruit is rich in Vitamin C (c. 200mg/g). The fruits, which fall and accumulate beneath the trees in large numbers, can be eaten ripe, but are far more popularly used to brew beer. Its high pectin content, and delicious flavor, makes it ideal for jelly, and it has also been used for sweets, liqueurs, syrup and preserves.
The seed kernel, though hard to extract from the seed, is also tasty, and widely eaten. The kernels and the oil are said to be effective meat preservatives, whilst the oil is often used for culinary purposes, as well as being a traditional skin moisturizer.
Properties of Marula oil
The oil is predominantly oleic acid, which makes it an excellent component in skin-care formulations, while also containing linoleic, palmitic and stearic acids. It is also tremendously stable, outperforming all known natural liquid oils.
The combination of high nutritional value and excellent stability make it an excellent choice for modern cosmetic formulae. As it is easily absorbed, it can be used as light body oil in aromatherapy, or as the focal point for a range of tropical moisturizing lotions.