Essential oils: Mopane & sarcocaulon

Colophospermum mopane & Sarcocaulon mossamedense

Arid areas are characterised by extreme temperatures, low and variable rainfall, and high evaporation rates. These harsh conditions result in diverse ecological habitats, where vegetation is adapted to the unique conditions. Adaptations of desert plants to their environment involve a variety of strategies from physiological adaptations to store moisture, to morphological features such as hairy or waxy layers on their leaves and stems to restrict moisture loss and/or protect them from insolation. The incidence of aromatic plants is high in arid environments, and desert plants are known for their ability to produce aromatic gums, waxy barks and resins.

True gums are formed from the disintegration of internal plant tissues, usually of cellulose composition. They exude naturally from the stems of plants or in response to wounding of the plant, and are colloidal and soluble in water. Gums contain high amounts of sugar, and are sometimes so sweet that they are eaten. In the arid area in north-western Namibia, the sweet-tasting, edible gums of Terminalia prunioides and Acacia erubescens are favoured.

Resins are very complex and varied in chemical composition. Usually secreted in definite cavities or passages, the resin frequently oozes out through the bark, hardening on exposure to air. Due to their high antiseptic qualities, resins probably serve the plant by preventing decay. They may also lower the amount of water lost from the plant tissues and are likely to deter herbivores by making the plant tissues bitter and unpalatable. Unlike gums, they are insoluble in water, but dissolve in various inorganic solvents such as alcohol and ether.

Owing to its antiquity, the Namib Desert is home to endemic species, mostly highly adapted to the specific climate of the area and often aromatic, as is characteristic of many desert-adapted species. In addition to the highly aromatic commiphora species found in north-western Namibia, which is a centre of diversity for that genus, there are many other species that potentially could be harvested for the extraction of essential oils.

Other than the gums and resins produced by commiphora species, there are two other plants that are currently being harvested in the Kunene Region for the production of essential oils.

  • The seeds of Colophospermum mopane are harvested and steam distilled at the Opuwo Processing Facility to extract an essential oil
  • The waxy bark that remains on the soil surface after Sarcocaulon mossamedense plants have died and decomposed is collected. The extraction of the essential oil from this material cannot be done by steam distillation. Solvent extraction methods are used and, at the moment, the possibility of doing this extraction in Namibia is being explored.

The products from the two plants discussed in this chapter provide very different challenges. The mopane resource is abundant and the technology for extraction locally available. The challenge is to develop the market. The Sarcocaulon resource, on the other hand, is limited and technology for adding value is not available within Namibia, but there is considerable market interest in the product. Before either of these products can be sold in the EU, the regulatory documentation is required.

The name Colophospermum is Greek for resin seed (‘kolophonios’ resin; ‘sperma’ seed). Colophony is another name for rosin, a substance with a turpentine-like smell obtained from pine trees. The species name, mopane, is taken from the Tswana name for the tree.

The wood of C. mopane has many well-documented uses in Southern Africa, such as quality firewood, timber for building walls and roofs and making utensils such as cattle yokes. The bark is used for tanning and to produce rope, while the foliage provides dry season browse for game and livestock. One of the most important uses of this species is that it is a food plant for the edible mopane worm (Imbrasia belina), which is highly nutritious and is regarded by many indigenous people as a delicacy, besides also being eaten by animals and birds. Medicinal uses vary from the treatment of sore eyes, to treatment of chafing of the inner thighs, stomach pains, kidney stones and as a cure for madness. The leaves are used to disinfect wounds and reduce bleeding by promoting clotting.

While these many uses of mopane have been documented, there is very little reference to the use of the seeds of C. mopane. Although the seeds have a relatively high crude protein content animals do not generally eat them. There are secondary metabolites in spots of resin on C. mopane seeds which are not present in the leaves, and these presumably protect the seeds from being eaten by making them unpalatable.

The start of the commercialisation process of mopane seed in Namibia can be identified by the work done by Laura Weiss. Her thesis considered the ecological and social feasibility of C. mopane seed commercialisation in Namibia and concluded that the resource was in abundant supply and that commercialisation was unlikely to result in any negative social or ecological impacts.

  • In 2006, IRDNC started organising and mobilising harvesters in selected conservancies and a trial harvest was undertaken.
  • The Opuwo Processing Facility was developed with funding from the ICEMA project and FFEM, with technical support provided by Pierre du Plessis. MCA-N supported the operationalisation and upgrading of the facility by providing equipment and technical support through the INP PPO Support Activity, as well as through two Innovation Fund grants.
  • The processing of mopane seeds at OPF started in 2011.
  • Funding from MCA-N supported the product and market development of C. mopane oil, with support from the Natural Resources Institute, V. Mane Fils and Phytotrade Africa.
  • In 2012, South African companies, Frazer Parfum and Terres d’ Afrique, purchased mopane essential oil to include in their products.

Sarcocaulon mossamedense is a semi-erect bush with spiny branches and pink flowers. When the plant dies and the woody parts have decomposed, a waxy bark remains on the soil surface for extended periods. The bark can be processed using solvent extraction methods, and the resulting aromatic extract used in cosmetic products. Because only the dead plant material is used there is no obvious ecological threat to the species from harvesting the plant material. This material is not known to be used by animals in any way. Participatory resource assessments indicated that there is no local traditional knowledge associated with this species and it appears to be of little value to the Himba communities, who refer to it as okamuti, meaning small tree.

The lack of a more descriptive name indicates that the plant had received little attention from local residents until the possibility of collecting it to sell became known. Useful plants usually have descriptive names. French companies, Behave and V. Mane Fils, showed and early interest in this resource.

  • The IRDNC has undertaken resource assessments in the Puros, Okondjombo, Sanitatas and Orupembe conservancies and community forests. Very limited amounts of this resource are found in the western extent of Okondjombo and Sanitatas where these conservancies and community forests are adjacent to the Skeleton Coast Park.
  • Training has been provided to harvesters from the Puros and Orupembe conservancies and community forests in correct harvesting techniques. Only the dark wax, which remains on the soil surface after the plant has died and decomposed, is collected. While the plant is alive, the wax is a yellow colour and almost impossible to separate from the woody stems.
  • Buying points have been established where conservancy staff monitor the harvesting activities and check the quality of the harvested material.


Colophospermum mopane is the dominant woody species over much of the arid parts of Southern Africa. The genus Colophospermum only occurs in Africa and includes only one species. C. mopane has many common names throughout its range, including: mopane, butterfly tree, turpentine tree, Rhodesian ironwood, omutati and omusati. Mopane trees grow in hot, dry, low-lying areas, in the far northern parts of South Africa, into Zimbabwe, Mozambique, Botswana, Zambia, Namibia, Angola and Malawi. It is found in alluvial and shallow alkaline soils which do not drain well.


Sarcocaulon plants, which belong to the Family Geraniaceae, are found only in the western parts of South Africa, Namibia and Angola. The name Sarcocaulon originates from the Greek words for fleshy (sarkos) and stems (kaulos). These plants have fleshy branches that are covered with waxy, translucent bark. They grow in arid areas and are generally found on rocky hillsides or mountainsides.

Sarcocaulon mossamedense was first collected in Angola by Welwitsch in 1859, and is the only species of Sarcocaulon that occurs outside of South Africa and Namibia. It is found from Henties Bay to just north and east of the port of Mossamedes in Southern Angola. It grows in extremely arid and bare localities, usually among rocks. It has been recorded in the Puros, Sanitatas, Okondjombo and Orupembe conservancies, as well as in the Skeleton Coast National Park. Populations of S. mossamedense are typically localised but, where they do occur, they can be found in high densities. Plants near the coast are dependent to a large extent on coastal fog for their water.


Mopane seeds are collected by harvesters from the Sesfontein, Anabeb, Otjiu-West, Okongoro and Orupupa conservancies. Harvesting takes place from June to September, once the fruits have matured. Annually close to ten tons of seeds are harvested by about 400 harvesters. Seeds that have dropped from the trees recently, are also harvested. Harvesters are paid N$2.50/kg when they deliver the material to the conservancy buying points. The seeds are packed in bags, labelled and transported to the processing facility, where they are steam distilled to extract the essential oil.

Since the bags of harvested mopane seeds are bulky, and the extraction rate of essential oils from the small spots of resin on the seeds is low, the development of this product would have been impossible without a local facility to do the essential oil extraction. The available resource is abundant and the technology is functioning well. However, marketing of this product remains a challenge.\


Resource inventories in the northern conservancies of the Kunene Region have indicated that most of the material available for collection is found in the Puros and Orupembe conservancies and, for this reason, research and training activities have focussed on those areas. Following resource inventories, fixed sites for monitoring have been established to monitor the population trends over time.

Small quantities have been harvested in the Puros and Orupembe conservancies and community forests. Harvesters need to be registered and attend training on appropriate harvesting methods before they are allowed to participate in harvesting activities. The estimated annual sustainable yield from these conservancies is between 1.6 and 2 tonnes. Currently, all raw material is purchased by V. Mane Fils and processed in France.

The Opuwo Processing Facility has received ongoing support from the MCA-N throughout the Compact period. This started with support from a technical expert to operationalise the stills at OPF and to make the necessary adaptations to get the stills functional. Ongoing technical support and equipment has been provided as well as support for product and market development through two Innovation Fund grants (NEOi and NOBO). During this quarter a new commiphora still was installed and operationalised as well as a cooling system.

The official opening that took place on 27th February 2014 was to launch not only OPF but also the Visitor’s Centre. The event was attended by representatives from MCC, MCA-N, NRI, CDSS, IRDNC and most importantly the owners of this development, the Kunene Conservancies Indigenous Natural Products Trust and the harvesters. Wet weather conditions made it a challenge for many to attend the opening but in spite of this, most of the key stakeholders were present.

The harvesters looked beautiful and self-assured as they sat in front of the proceedings and were duly honoured by the keynote speaker, Governor Hoebeb of the Kunene Region, as the keepers of the desert garden. One of the highlights for the harvesters was the viewing of the Visitor’s Centre DVD in which several of them featured. While these proceedings were taking place, the commiphora still was operating so guests experienced the wonderful fragrances and were able to view the distillation process and the production of the essential oil.

The sustainable harvesting of gums and resins and the production and successful marketing of Namibian essential oils has the potential to make a significant impact on the livelihoods of many Namibians living in remote rural areas. Over the past ten years, much research has been done and this has laid the foundation for the successful establishment of sustainable supply chains. The development of sustainable markets for these products is the next challenge for the Namibian organisations supporting INP development.