Welwitschia mirabilis

Welwitschia mirabilis

Welwitschia, also known by the evocative name “two leaves that cannot die” (Welwitschia mirabilis Hook. f.), is a herbaceous species belonging to the family Welwitschiaceae.

Systematics –
Domain Eukaryota,
Kingdom Plantae,
Division Gnetophyta,
Class Gnetopsida,
Order Welwitschiales,
Family Welwitschiaceae,
Genus Welwitschia,
Species W. mirabilis.
The following terms are considered synonyms:
Tumboa bainesii Hook.f.;
Welwitschia bainesii (Hook.f.) Carrière;
Tumboa strobilifera Welw.;
Welwitschia mirabilis subsp. mirabilis;
Welwitschia mirabilis subsp. namibiana Leuenb.;
Welwitschia namibiana (Leuenb.) Christenh. & Byng.

Etymology –
The scientific name Welwitschia mirabilis already encompasses part of the history and uniqueness of this plant. The genus Welwitschia was named after the Austrian botanist and physician Friedrich Welwitsch, who encountered the plant during his explorations in Angola in 1859. Its formal scientific description was later published by Joseph Dalton Hooker. The specific epithet mirabilis derives from Latin and means “wonderful”, “extraordinary”, or “worthy of wonder”. In its case, the name seems particularly appropriate.
Welwitsch was deeply impressed by his discovery. He recounted that he stopped to observe the plant almost in disbelief, wondering whether it might be an illusion. He had previously proposed naming the plant Tumboa, after the local name N’tumbo. Hooker, however, preferred to dedicate the genus to its discoverer.
The species has numerous common names. In English it is also known as tree tumbo, while in Afrikaans it is called tweeblaarkanniedood, an expression that can be translated as “two leaves that cannot die”. Local names include kharos and khurub in Nama, nyanka in Damara, and onyanga in Herero. The latter name is generally interpreted as “desert onion”, probably referring to the appearance of the basal part of the plant.

Geographical Distribution and Habitat –
Welwitschia mirabilis has an extremely limited distribution. It is endemic to the Namib Desert, along a belt of south-western Africa extending from southern Angola to central and north-western Namibia. Its range stretches for more than one thousand kilometres along the Atlantic coast.
The Namib is one of the most arid environments on the planet. In some areas, rainfall is extremely scarce and may be virtually absent for long periods. The plant grows on gravel plains, in temporary riverbeds, on slopes, and in desert areas close to the coast. Populations are often associated with locations where groundwater can be found or where greater moisture availability occurs.
The survival of Welwitschia is the result of a series of highly sophisticated adaptations. The main root can penetrate deeply into the soil, while the shallower root system helps intercept water originating from the condensation of coastal fog. The large leaves also play an important role. Their surface can in fact facilitate the capture of atmospheric moisture, which subsequently reaches the ground.
The plant is therefore closely linked to the particular climatic balance of the Namib. This specialization is also one of its main vulnerabilities. The overall population is currently considered relatively stable, and the species is classified as Least Concern according to the criteria reported by Kew, but its distribution remains confined to a highly specialized environment. Overgrazing, disease, the collection of specimens, vehicle damage, and climatic changes may therefore represent significant threats.
Recent studies have also highlighted how ancient the evolutionary history of the species is. The genome of Welwitschia mirabilis, sequenced at the chromosome level in 2021, has a size of approximately 6.8 billion base pairs. The genomic characteristics identified help explain the plant’s extraordinary ability to tolerate high temperatures, water scarcity, and prolonged environmental stress.

Description –
At first glance, a Welwitschia almost looks like a fragment of vegetation abandoned on the sand. Its stem is extremely low and massive, forming a sort of large woody disc known as the crown. From this structure arise the two most remarkable characteristics of the species: its two permanent leaves.
The plant initially produces two cotyledons, that is, the first embryonic leaves. It subsequently develops its two definitive leaves. These are the only true leaves that will accompany the organism throughout its entire life. Unlike most plants, in fact, they do not stop growing after reaching a certain size. The meristematic tissue located at their base allows them to continue elongating for decades and even centuries.
Over the years, the leaves can reach several metres in length. Wind, sand, and climatic forces progressively tear them apart, transforming them into long green and brown strips that become tangled across the ground. For this reason, the oldest specimens can take on an almost chaotic appearance. The plant, however, continues to produce new tissue at the base of the leaves.
The height of Welwitschia is modest. Some large specimens can reach approximately one metre or slightly more above the ground, while the leaves can extend for several metres. Kew describes specimens whose leaves can reach around four metres in length, while exceptional individuals can develop a crown of considerable size.
Another extraordinary characteristic is its longevity. Many individuals are probably several hundred years old, and some specimens have been estimated to be more than a millennium old. The highest estimates reach approximately two thousand years. For this reason, Welwitschia is often referred to, in popular-science terms, as a “living fossil”. This expression does not mean that it has remained unchanged since ancient times, but rather emphasizes the great antiquity of its evolutionary lineage and the presence of extremely peculiar morphological characteristics. Genomic studies have indeed confirmed the evolutionary depth of the species and its extraordinary capacity for adaptation.
Welwitschia is a dioecious plant: there are therefore male individuals and female individuals. Both produce reproductive structures resembling small cones. Male cones produce pollen, while female cones produce ovules and subsequently seeds. The cones also produce sugary substances that attract insects. Flies are the most important pollinators, while bees and wasps may occasionally contribute. Wind appears to play a much more limited role.
Once pollination has occurred, the seeds may take many months to mature. They are lightweight and possess structures that facilitate dispersal by wind. The plant must therefore reconcile extremely slow growth with an equally delicate reproductive process.

Cultivation –
Cultivating Welwitschia is possible, but it requires care. The plant is generally propagated from seed and is grown in various botanical gardens and specialized collections. Kew reports that the seeds can germinate rapidly, while the subsequent stage, namely the growth of the young plant, is considerably more delicate.
The main problem is the root system. Young plants rapidly develop a robust taproot and require sufficiently deep containers. Transplanting must be carried out with particular care to avoid damaging the root.
Drainage is also essential. A very free-draining substrate, consisting for example of coarse mineral materials, makes it possible to provide water without creating waterlogging. Young plants may have different water requirements from adult specimens: under controlled conditions, they can be kept somewhat moister during the first stage of growth, whereas mature specimens should be cultivated under conditions that reproduce, as far as possible, the alternation between aridity and water availability typical of their natural environment.
One of the most serious problems during germination is fungal infection. Seeds collected in the wild may be contaminated by Aspergillus niger, a fungus capable of compromising their germination. For this reason, botanical collections pay particular attention to seed quality and substrate hygiene.
Light requires just as much attention. An adult plant is perfectly adapted to the desert environment, but young cultivated Welwitschias may suffer from sudden exposure to very intense solar radiation. Excessive light can cause reddening of the leaves and severe physiological stress. Kew also emphasizes that, once germinated, the plant requires particular care, especially with regard to watering and root protection.
Propagation from seed also offers an important advantage: it preserves the genetic variability of the species. In cultivation, specimens with unusual characteristics have even been observed, such as abnormalities in the number of leaves or variegation.

Uses and Traditions –
From a taxonomic standpoint, Welwitschia is a monotypic genus: it comprises only one living species, Welwitschia mirabilis. It is the only extant genus of the family Welwitschiaceae and the order Welwitschiales. It belongs to the Gnetophytes, an ancient group of gymnosperms that also includes the genera Gnetum and Ephedra. The evolutionary relationships of the Gnetophytes have long been debated; modern molecular analyses place them within the gymnosperms and indicate a particular evolutionary affinity with conifers.
Welwitschia is not a plant primarily cultivated for food or medicinal purposes. Its interest is mainly botanical, scientific, cultural, and ornamental. It is one of the most recognizable organisms in the flora of southern Africa and has become a true icon of the Namib Desert.
It also plays a particular role in the culture of local populations. The Damara and Herero traditionally use the female cones as food. According to Kew sources, the cones can be eaten raw or cooked, including by roasting them. This tradition is also reflected in the Herero name onyanga, generally translated as “desert onion”.
It is important, however, not to turn this information into a modern dietary recommendation. The traditional use of the cones is an ethnobotanical aspect of the species and does not constitute a recommendation to consume them.
The plant also has strong symbolic value in Namibia. A Welwitschia is depicted on the national coat of arms of Namibia, where it represents one of the characteristic elements of the country’s landscape and natural heritage.
From an ecological perspective, the plant also plays an interesting role. A large specimen can constitute a kind of small “island” in the desert. The leaves and crown provide shelter and shade and can create locally different conditions compared with the surrounding ground. Some animals also feed on the leaves. Welwitschia thus contributes to the complex web of relationships that characterizes one of the most extreme environments on Earth.

Preparation or Methods of Use –
From a food perspective, the traditionally used part is the cone, particularly the female cone. Ethnobotanical sources report two main methods: eating it raw or cooking it, including directly among hot embers. Kew confirms both methods in the food traditions of the Damara and Herero.
The name onyanga, “desert onion”, can be misleading: it is naturally not an onion belonging to the genus Allium, but rather a traditional name associated with the appearance and use of the plant product.
In cultivation, the plant is instead used mainly as a collector’s specimen and as a subject of research. Propagation is carried out by seed. In botanical gardens, reproduction can be facilitated through manual pollination, using pollen from male plants and transferring it to female cones. The seeds are then collected when mature and germinated under controlled conditions.
Welwitschia therefore represents a singular case also in terms of human use. It is neither a domestic plant nor a conventional agricultural crop. Rather, it is a species in which botany, ethnobotany, culture, and conservation come together. Its ability to live for centuries in the desert, continuing to produce just two leaves that never truly stop growing, remains one of the most remarkable examples of adaptation in the plant kingdom.

Guido Bissanti

Essential Sources
For taxonomic and geographical information, the main source used was Plants of the World Online of the Royal Botanic Gardens, Kew, which recognizes Welwitschia mirabilis as an accepted species and indicates its range in Angola and Namibia.
For evolutionary and genetic aspects, the study published in 2021 in Nature Communications, focusing on the species’ genome and the mechanisms underlying its longevity and tolerance to environmental stress, was used.
For pollination and cultivation, information from the Botanical Conservatory of the University of California, Davis, and Kew was consulted.
For traditional and cultural uses, Kew documents in particular the consumption of the cones by Damara and Herero communities and the presence of Welwitschia on the national coat of arms of Namibia.

Other Sources
Acta Plantarum – Flora delle Regioni italiane.
Wikipedia, the free encyclopedia.
GBIF, the Global Biodiversity Information Facility.
Useful Tropical Plants Database.
Conti F., Abbate G., Alessandrini A., Blasi C. (eds.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
Treben M., 2000. La Salute dalla Farmacia del Signore, Consigli ed esperienze con le erbe medicinali, Ennsthaler Editore.

Photo source:
– https://www.inaturalist.org/observations/270216861

Please note: Pharmaceutical applications and uses as food are indicated for informational purposes only and do not constitute medical advice; therefore, no liability is accepted for their use for therapeutic, cosmetic, or dietary purposes.