Acanthosicyos horridus

The Namib Desert is hyper arid, with sandy to rocky habitats that host a myriad of life forms that have evolved and adapted to harsh and unhospitable conditions. One of the most striking examples of adaptation to arid conditions is the desert cucurbit, !Nara (Acanthosicyos horridus Welw. ex Hook.f.). The second part of the scientific name says it all – it is easily distinguished by its exceptionally spiny habit – but its rather formidable appearance belies the fact that this plant is a treasured and essential desert element. Not only does this flagship species play a vital support role to other organisms in the desert ecosystem, but is inextricably linked with desert-dwelling people to whom it offers a lifeline of sustenance, deeply entrenched within their cultural heritage. It can thus be considered both a keystone ecological and a keystone cultural species.

!Nara is a leafless, thorny, melon-bearing bush that is endemic to the Namib Desert. The plants occur sporadically throughout this coastal desert from Port Nolloth in South Africa (last recorded in 1925) to Namibe in Southern Angola, with the greatest concentrations around the Kuiseb River Delta, and the most eastern distribution from around Sossusvlei. Recent explorative fieldwork has improved understanding of a more widespread occurrence in westward flowing ephemeral rivers of the northern Namib.

Plants are restricted to sand desert, often at the base of dunes, and are mostly associated with rivers ending in or flowing through the Namib, and their palaeochannels. They are absent from stony desert plains.

The plants form hummocks, which may extend over large surface areas, 1500 m2 or more, ever-increasing as the sand continues to accumulate around the plant. The spiny domes of stems may project a centimeter to one meter or higher above the hummocks. !Nara, where it occurs, is usually the dominant feature in the landscape and is not associated with other vegetation, since few other plants can survive the wind-borne sand and rainless climate. The tangled, grey- to yellow-green masses of stems enable it to be easily recognised from a distance. As the plants are leafless, a desert adaptation taken to the extreme, it is these ridged stems and paired spines of 20–30 mm long, making up almost 50% of the total surface area of the plant, which enable the plant to photosynthesise. A thick, robust tap-root system, which may extend more than 50 m below the surface, efficiently draws moisture from deep underground. This, coupled with structural adaptations to limit evaporative water losses from the surface of the plant, enables the !nara to survive for many years without rain.

The plants are dioecious (male and female flowers on separate plants), with male flowers appearing throughout the year, and female flowers mostly during spring. Sex expression in cucurbits is controlled by environmental as well as genetic factors, and may explain discrepancies in the life-cycle events, such as flowering of northern populations, revealed during recent fieldwork.

!Nara fruit are round and melon-like, weighing mostly around 1 kg but sometimes reaching up to 2.5 kg. They are pale-green even when ripe, and spiny on the outside. The fruit has a mass of watery, orange-yellow pulp, which is sweet and aromatic, tasting like avocado or a cross between cucumber and pineapple. Toxic and potentially therapeutic compounds called cucurbitacins, which cause bitterness in the fruit, are currently under investigation in !nara. Further study of these compounds could elucidate taxonomic relationships; provide evidence to support the hypothesis of pre-selection as a husbandry practice; as well as present opportunities for novel pharmaceutical product development due to their professed anticancer properties. The large seeds are white to cream in colour with buttery kernels.

Acanthosicyos horridus is a member of the Family Cucurbitaceae, a pan-tropical group of plants that is not closely related to any other plant family, but which includes several economically important crop species such as pumpkins and melons. Southern Africa is an important centre of diversity for the family, of which 46 species in 15 genera occur in Namibia. Several of these, including !nara, are endemic or near endemic. The only other species within this genus, A. naudinianus (gemsbok cucumber) is found on deep Kalahari sands, in the drier parts of Southern Africa. Fresh fruit pulp is a refreshing snack and thirst-quencher, while ripe fruit is cooked and eaten as a vegetable.

Studies in the Central Namib, mostly conducted in partnership with the Gobabeb Research and Training Centre, have repeatedly demonstrated the fundamental and irreplaceable role of this plant within the ecosystem. It is both a direct and indirect source of food to animals, while also providing shelter to a host of desert organisms. At least 26 vertebrate species depend on !nara, while the hummocks provide habitat for a host of invertebrates.

Significant data exist that intimate a long history of use. Fossilised plant roots occurring in Tsondab Sandstone suggest that !nara may have existed for as long as the Namib dunes. The earliest evidence of human use was documented through the identification of seed coat fragments from an archaeological site at Mirabib Hill shelter near Gobabeb, dated at approximately 8,000 years old. Several millennia after the initial introduction of pottery to Namib inhabitants, the appearance of wide-mouthed, soot-covered clay pots at 800-year-old archaeological sites indicates local innovation of cooking !nara fruit. As evidenced by special praise songs that extol its virtue, !nara has a long association with and is central to the culture of the ≠Aonin/Topnaar people who have lived along the ephemeral Kuiseb River for more than 600 years.

Their renowned subsistence economy since precolonial times, based on a combination of harvesting natural resources on the verge of the desert and along the coast, and subsistence agriculture along the Kuiseb River, has been thoroughly documented, with most of this research focussed on the harvesting of !nara fruit. A maritime travel account from as early as 1677 records !nara use by indigenous people along the Namibian coast. British explorer, Sir James Edward Alexander, already found the inland region of the Kuiseb River to be densely populated with people and livestock in 1838, at which time the !nara was heavily but sustainably utilised.

However, historical sources and contemporary ethnography demonstrate other Khoekhoegowab-speaking peoples from elsewhere in the Namib, such as the Damara groups in north-western Namibia and the nonextant southern Namib Sān peoples still have or had similar practices and traditions, including inheritable exclusive utilisation rights. Harvesting !nara melons as a major food resource by some traditional communities has symbolically distinguished both the Kuiseb Topnaar and Damara peoples living from the Uniab to the Khumib rivers to be called !Naranin by their neighbours (a Khoekhoegowab name for people dependent on !nara). The Otjiherero-speaking Himba groups use the plant as an emergency food during famine and do not consider it a staple.

In the past, !nara fields were divided into patches and allocated to different families, passing on to successive generations through inheritance, with ownership and access disputes resolved by the chief. This ensured sustainability of resource use. Today, however, !nara fields are largely commercialised, and have become a communal resource with no private ownership, thus affecting the direct relationship between the resource and those who have traditionally depended on it.

!Nara harvesting, during January to April, is a timeand labour-intensive process that requires an average of three hours to gather one kilogram of seeds. Harvesters usually spend four months at harvesting sites, collecting !nara for up to 11 hours a day, travelling to and between hummocks by donkey cart or on foot. A simple harvesting technique is employed – melons are loosened and teased from the thorny branches with long, wooden sticks. The modern use of hooked iron rods, often used indiscriminately by the inexpert, can damage the fruit and bushes. The general rule is that when the melon is yellowish, the fruit is ripe enough to harvest. Unripe fruits are collected and covered with sand and plastic to ripen for three days. Harvested melons are then collected and returned to the huts in donkey carts. Harvesting is mostly undertaken by men, while women are mainly responsible for the processing.

The entire fruit is processed into a cornucopia of products. Sweet, juicy fruit flesh is eaten raw or cooked into a pulp. This processing involves scooping out and boiling the fruit flesh in large drums over open fires. Once reduced to half its volume, while being continuously stirred with long sticks, the pulp is strained and the seeds are removed. The pulp is eaten with porridge, or sun-dried for several days directly on sand or, more commonly of late, on plastic sheets to make ‘!nara chocolate’. This fruit-roll product, rich in vitamins, minerals and trace elements, is eaten on its own or with cooked maize porridge. The delicious, highly nutritious dried seeds, containing 57% oil and 31% protein, are relished as a snack. Both the chocolate and seeds are easily portable, can be stored without spoiling, and are eaten over many months. Not wanting to waste even a fraction of this valuable resource, the peels of !nara fruit discarded during processing are fed to donkeys and goats, and the unwanted seeds to chickens.

Although its importance as a staple has declined in recent years, being substituted by western food commodities, !nara is still consumed by the Topnaar because of its high nutritional value and their strong cultural association with this local food source. It remains a primary source of income and food security in many rural Topnaar households.

Medicinal uses of !nara abound and it is an important element in the traditional Topnaar pharmacopoeia. Eating fresh fruit pulp relieves stomach ache, while a decoction of roots is used as a ‘life-elixir’ to cure internal diseases; crushed root mixed with oil is smeared on wounds to hasten healing. Cosmetic applications include using the oil from raw or roasted seeds as a skin moisturiser or sunscreen.

Some information, although largely anecdotal, exists for the formal !nara trade. Early accounts from the late 19th Century mention the export and sale of the seeds to the confectionary trade in South Africa, where they were marketed as ‘butterpits’. This trade increased and reached a peak in the 1970s, when an estimated 26 tonnes of seed were traded annually. Over the ensuing years there has been a steady decline in trade from 15 tonnes per annum in the 1990s to less than four tonnes per annum. This trend has been ascribed to various factors, that range from environmental, e.g. the decline in the resource, to socioeconomic, such as change in cultural practices and alternate livelihood options; decrease in consumer demand; limited investment to explore product diversification.

As with all wild plant species, !nara fruit yields can vary considerably between and within populations, and are significantly impacted by a slew of external factors, including weather conditions and predation. A range of 20–500 melons has been recorded per individual bush, while each fruit can contain 50–200 seeds. Some 10–20 melons are required to yield 1 kg of seed. Using local knowledge, higher yielding, better quality fruit can be identified. Harvesters also recognise and differentiate between fruit with seeds to be retained for own consumption, shared with relatives, or sold.

The current value chain is contained largely in-country . While primary production (harvesting) and processing of !nara melons are undertaken at household level, commodification follows two distinct market pathways. So-called ‘coated’ seeds are sold for direct consumption, primarily to consumers in Walvis Bay, in 1–2 kg plastic bags, with prices ranging from N$10 to N$20 per bag.

Harvesters also trade ‘uncoated’ seeds with Desert Hills, a Swakopmund-based, small-scale manufacturer, at a price of N$22/kg. Currently, only about 15 harvesters supply seeds to Desert Hills, but many more offer seeds for sale after the harvesting season. Due to the small-scale nature of its operations, the seed demand from this enterprise is limited to about 3–4 tonnes per year.

Desert Hills further dries and sorts the seeds to ensure that only high-quality, uncoated seeds are processed to ensure good-quality endproducts. Value-addition processes include the cold pressing of fine virgin oil that is used in a variety of food and natural cosmetic products. The seed cake residue from the oil pressing is sold as livestock fodder to local farmers for N$2.50/kg.

In 2004, the annual !nara seed harvest averaged about 490 kg per harvester, of which about 200–250 kg were sold. Based on prices at that time (N$6–8/kg), the average annual income from seed sales was about N$1,200–2,000 per harvester. These earnings were and still remain critical for the Topnaar harvesters, some 40% of whom have no other source of revenue. On average, about 43% of annual income derives from selling seeds, supplemented by state pensions and livestock keeping.

Although the !nara has obvious economic potential, sales volumes have steeply declined with the cessation of exports. Current income from seed sales is minimal, therefore commercial viability remains low. Investment into product diversification and development, supported by an improved understanding of the supply chain required to support value-addition, may open up opportunities to more fully exploit this resource.

Products from !nara

The oil produced from the seeds is bottled or mixed with other ingredients in food products or cosmetics. These products are available at the on-site Desert Hills outlet, as well as selected retailers in Namibia. International speciality cosmetic companies, such as The Body Shop, have previously expressed interest in the oil, but have been deterred by concerns regarding guaranteed supply of raw material.

Future of a nascent !nara industry

Given the obvious promise of !nara, it is somewhat surprising that the plant has not been prioritised in relevant INP programmes in Namibia. This reluctance has been ascribed to a plethora of complex and sensitive ecological, economic and social issues. During the early 2000s, a concerted effort to initiate multidisciplinary investigations into the biology and economics of this species was spearheaded by the Gobabeb Research and Training Centre and endorsed by the Topnaar Traditional Authority. The INP sector in Namibia has since matured and is gaining international credibility with the development and marketing of several successful plant derivatives, coupled with fair and effective benefit-sharing arrangements. A current resurgence of interest in the species, from a scientific as well as a development perspective, coupled with appropriate investment and a shared vision for its development, may elevate the !nara to its rightful place on the INP platform.

  • A thorough investigation into the reported decline in yields from wild populations, coupled with agronomic trials to determine its cultivation requirements, will address concerns expressed regarding sustainability of supply, a prerequisite for investment by international concerns.
  • Transdisciplinary studies can elucidate the centre of origin and diversity of this species, allowing for tracing back its ancestry and testing the hypothesis that this species has been preselected for certain agronomic traits by desert-dwelling people in ancient times. Valuable insights may be gained as to the evolution of farming as a land-use in Namibia.
  • Scaling-up commercial exploitation opportunities using the fruit flesh, as well as seed oil, and exploring pharmaceutical benefits of cucurbitacins, should be considered to expand the portfolio of products from this species. This charismatic species, with strong cultural associations, is preconditioned to be a Namibian product to be marketed as a natural and exotic ingredient.
  • !Nara knowledge and cultural heritage appears to be much more complex than the current under standing that limits this culturally and geographically to the ≠Aonin / Topnaar of the Kuiseb. This has implications for the safeguarding of intangible cultural heritage, and for the development of access and benefit-sharing arrangements arising through commercialisation of species with existing indigenous values. In-depth ethnographic work can assist with ensuring inclusivity and fairness that acknowledges such complexity.
  • Changing cultural practices and increasing pressure from outside harvesters from Walvis Bay may shift utilisation to become unsustainable – “tragedy of the commons” effect. More effective regulation through the introduction of a harvesting permit system, issued through a national competent authority is required.
  • A multi-phased business model for enhanced efficiency and value of the !nara commercial market should be developed, and support secured for its implementation. This model should incorporate the organisation and registration of harvesters as a Producer and Processor Organisation (PPO) or cooperative, equipped to manage resource use, and their capacity should be developed to maximise economic benefit to the community. Successful business models developed for other INP commodities in Namibia, such as Commiphora resin, exist and could provide useful lessons learnt. Ultimately, a more influential role and a greater share of the benefits derived along the entire value chain should accrue to the harvesters.
  • Understanding the generational dynamics regarding traditional practices is key to ensuring the ongoing viability of the entire !nara market system, and strategies need to be considered to incentivise Topnaar youth to embrace these preactices, for example micro-opportunities for value addition within the harvester community.