Weird, peculiar, wonderful, strange, bizarre, fascinating, and
of course, unique, are the kind of words that are used to describe
the welwitschia. It is one of the few things on Earth that can truly
claim to be one of a kind. There really is nothing like it.
An adult welwitschia consists of two leaves, a stem base and roots.
That is all! Its two permanent leaves are unique in the plant kingdom.
They are the original leaves from when the plant was a seedling,
and they just continue to grow and are never shed. They are leathery,
broad, strap-shaped and they lie on the ground becoming torn to
ribbons and tattered with age. The stem is low, woody, hollowed-out,
obconical in shape and sturdy. It grows to about 500 mm in height.
The largest recorded specimen is in the Messum Mountains and is
1.8 m high, and another on the Welwitschia Flats near the Swakop
River is 1.2 m tall and 8.7 m wide. Carbon dating tells us that
on average, welwitschias are 500-600 years old, although some of
the larger specimens are thought to be 2000 years old. Their estimated
lifespan is 400 to 1500 years. Growth occurs annually during the
The sexes are separate, i.e. male plants and female plants. The
male cones are salmon-coloured, small, oblong cone-like structures,
and the female cones are blue-green, larger and more tapering. At
Kirstenbosch, they flower from midsummer to autumn. The male flower
has a sterile, modified pistil-like structure, which exudes nectar
(50% sugar content) from a modified stigma-like structure. The female
cone has exposed stigmas and also produces a nectar droplet.
Male cones in flower
Close- up male cone
Female cones in flower
Female close-up once hand pollinated
Female cones - fertilized.
Cone-bearing plants are often wind pollinated, producing masses
of pollen and all at the same time. Welwitschia is clearly
not wind pollinated, as it produces smaller amounts of pollen, with
the nectar to attract insects, and the flowers open in succession
over an extended period, which also encourages cross-pollination.
It may be a beetle, but judging by the fact that large distances
can separate plants, Ernst van Jaarsveld thinks it is more likely
to be a kind of wasp, which he has seen on the male cones in habitat.
The female cones reach maturity in the spring, about 9 months after
The seeds are 36 x 25 mm and have a large papery wing and are
dispersed by wind, in spring, when the female cone disintegrates.
In their natural habitat, many seeds are lost to fungal infection
and to small desert animals that feed on them. The seeds remain
viable for a number of years. They germinate only if fairly heavy
rain is spread over a period of several days. As these conditions
rarely occur, it often happens that many plants in some colonies
are the same age, as they all germinated in the same good year.
The seedlings, once established,depend on the fog for survival until
the next rains occur.
There are more remarkable features that make Welwitschia
so difficult to categorise:
Unlike any other plant, the apical growth point of the stem stops
growing from an early stage. This causes the stem to grow upwards
and outwards, away from the original apex (which remains dead),
resulting in the characteristic obconical shape. In older specimens,
continued growth results in the undulating of the stem margin. This
growth habit is unique.
Like other cone-bearing plants (gymnosperms e.g. pines and cycads)
it is a dioecious (male and female separate) cone-bearer with naked
seeds, but the male 'flowers' or microstroboli are reminiscent of
the flowering plants (angiosperms).
The water-conducting tissue (xylem) is also typical of the angiosperms.
Welwitschia mirabilis grows in isolated communities in the
Namib Desert, in a narrow strip, about 1 000 km along up the coast
from the Kuiseb River in central Namibia to Mossamedes in southern
Angola. The plants are seldom found more than 100 to 150 km from
the coast, and their distribution coincides with the fog belt. Welwitschia
is still common in its habitat and shows variability, which is a
sign that it is far from extinction. They are neither endangered
nor rare, nevertheless they are protected by law.
Welwitschia is ecologically highly specialized, and is
adapted to grow under arid conditions receiving regular fog. This
regular, dense fog is formed when the cold north-flowing Benguela
Current meets the hot air coming off the Namib Desert. The fog develops
during the night and usually subsides by about 10 a.m The leaves
are broad and large and droop downwards. This is an ideal way for
it to water its own roots from water collected by condensation.
It also has numerous stomata on both leaf surfaces and fog-water
is taken up directly through these stomata. The fog has been estimated
to contribute 50 mm in annual rainfall, but in spite of the fog,
the plants are still dependent on additional sources. Rainfall in
this area is erratic and extremely low, only 10 - 100 mm during
the summer months. In some years, no rain falls at all. The plants
are often confined to dry watercourses or next to higher rainfall
regions, and they occasionally grow on rocky outcrops. All these
habitats point to an additional underground water supply. The plant
has a long taproot, allowing it to reach this underground water.
There are other interesting environmental adaptations. The largest
plants are found to the south where the rainfall is the least, whereas
in the north where the rainfall is higher the plants are much smaller.
The most likely reason for this is that the plants in the north
have to compete with savannah vegetation whereas those in the south
have little or no competition. Another interesting adaptation is
the corky bark, which could be the result of thousands of years
of exposure to grass fires so commonly associated with savannah.
Antelope and rhino chew the leaves for their juice during times
of drought, and spit out the tough fibres. They also eat the soft
part near the groove. This luckily does not damage the plant as
they simply grow out again from the meristematic tissue.
Uses & cultural aspects
core, especially of the female plant, was used as food for people
in earlier times. It is said to be very tasty either raw or baked
in hot ashes, and this is how it got its Herero name, onyanga, which
means onion of the desert.
Derivation of the name & historical aspects
Welwitschia mirabilis was discovered by the Austrian botanist,
explorer and medical doctor, Friedrich Welwitsch, in 1859 in the
Namib Desert of southern Angola. The story goes that he was so overcome
by his find that he knelt down next to it and simply stared! Thomas
Baines, the renowned artist and traveller, also found a plant in
the dry bed of the Swakop River in Namibia in 1861. Welwitsch sent
the first material of Welwitschia to Sir Joseph Dalton Hooker,
Director of Kew, in 1862. Hooker described it and named it in honour
of Welwitsch, despite the fact that Welwitsch recommended that it
be named Tumboa, its native Angolan name. Its species name
mirabilis means marvellous or wonderful in Latin. The specific
name was later changed to bainesii to honour both men involved
in its discovery, although mirabilis is the name recognized
Because it is so different from other gymnosperms, Welwitschia
was placed in its own family in a small order of gymnosperms called
the Gnetales. It shares this order with two other families each
containing one genus: the Gnetaceae (Gnetum, 30 species)
and the Ephedraceae (Ephedra, 40 species). All three genera
can stand by themselves, and the relationships between them are
remote. There is nothing else like them, and of the three, Welwitschia
is the most remote.
Welwitschia is thought to be a relic from the Jurassic period
when gymnosperms dominated the world's flora, its ancestor trapped
in an environment that slowly but progressively became more arid,
and all its close relatives long since disappeared.
Growing Welwitschia mirabilis
is not a true succulent, yet it is the succulent growers and enthusiasts
that are most interested in it. It is caudiciform, yet is not often
included in accounts of these plants as it belongs in the 'wrong'
family! Tree enthusiasts regard it as a tree driven underground.
Ernst van Jaarsveld, who has looked after the succulents at Kirstenbosch
since 1976 and who has been successfully cultivating welwitschias
in this time, regards Welwitschia as a terminally truncated
caudiciform, although initially semi-succulent, woody xerophyte.
To cultivate Welwitschia successfully, he recommends that
its peculiar native environment be simulated.
At Kirstenbosch, a Welwitschia House was custom-built in 1985,
containing raised beds with bottom heat, filled with mineral-rich,
well-drained, red "Vanrhynsdorp sand". Seed was sown in
1985 and one of the young plants flowered exactly two years and
six months later. This was a new record, and Ernst attributes their
success to the bottom heat during winter, the sand, and the regular
At first glance it would appear that Welwitschia would be
almost impossible to grow, but this is only partly true. Welwitschias
can be grown easily, even as pot plants and even on window sills
and verandahs in cooler climates. Once established, the plant will
grow steadily and is relatively disease free. The most crucial stage
is during its first eight months after germination when it is prone
to fungal attack. Also, as it is not a true succulent, it should
not be treated as one. It is dependant on additional water from
its roots and if grown in a pot, care should be taken that the soil
does not dry out completely.
When growing welwitschia there are a few important factors to take
into consideration: the long taproot, its dependence on extra moisture
and the soil used. Plants from arid regions are often lost to fungal
infection caused by soil with a high organic content. It is safer
to use a sandy mixture, water more frequently and give supplementary
feedings. It is also recommended to use sterilized soil. Older plants
tend to accumulate organic debris around themselves which enriches
the soil and acts as a mulch, helping to retain water in the upper
layers of the sand for longer.
should be sown during the warmer months, spring or summer. In habitat
the seeds are dispersed in spring, but have to wait for rain to
fall before they germinate. It is best to sow seed into a large,
deep (at least 30 cm, preferably more) container or into an open
bed where the plant is intended to remain, because the taproot grows
quite fast in the initial stages. If using a container, remember
to place a layer of gravel or rocks at the bottom to ensure good
drainage. The soil must be sandy and well-drained, e.g. 2 parts
sand : 1 part loam : 1 part compost (leaf mould) with ample bonemeal,
well mixed and sterilized. Moisten the soil thoroughly before sowing.
If using a container, sow two or three seeds per container, near
the centre. If more than one germinates, it can be transplanted
in its first month, or left to form interesting graft complexes
with its sibling. If you have an open bed, scatter them evenly over
the surface. Place the seed on top of the soil and just cover it
with a layer of sand. Water well and keep in a warm sunny situation.
It is important to add a mild fungicide, like Captan, to the water
during the first year as it will prevent fungal attack. Keep the
soil moist until the seeds have germinated.
The placement of the ungerminated and germinating seedlings is
also important. Choose a well-aerated, warm atmosphere, preferably
in filtered sunlight. The plants are very sensitive to sudden changes
in light intensity. Never move a plant from a shady situation to
full sun, the leaves will burn and the plant may never recover and
die. So when moving your plant, make sure that you gradually harden
it off to brighter light. Welwitschias in containers can be grown
in glasshouses, window sills, verandahs (stoeps) or outdoors in
areas with rainfall of below 500 mm per annum. In higher rainfall
areas, it may be quite happy on a slope. Also, we do not know its
frost tolerance. Just because its habitat is frost-free today, does
not mean that it did not have to contend with a colder climate during
its evolutionary history.
Germination should occur from 7 days to a few months after sowing.
The first sign is the cracking of the soil and the appearance of
the two cotyledons, initially pink in colour, becoming green. Initial
growth is very rapid, particularly the growth of the taproot. It
is essential that seedlings in a shallow tray be planted out as
soon as the cotyledons appear. Take care when transplanting, if
the root tip is damaged or broken, the seedling will die. Keep the
seedlings well watered during the first season. The warmer the temperature,
the faster they will grow. At Kirstenbosch, the temperature in the
Welwitschia House varies between 20 and 40 degrees C in summer and
growth is good - 20-30 mm high in three weeks with a taproot 50-70
mm long. It is better to give too much water than too little, but
remember the fungicide.
Seedlings should be watered regularly, at least once a week at
first, and later watering can be reduced to once every two weeks.
The amount of water also depends on the climate, cooler climates
requiring less watering than hot dry ones. During the natural resting
period in winter, watering should be reduced, and increased again
in late spring when the weather warms up again.
Welwitschia reacts well to being fed, and 'green up' and
grow a bit more rapidly in response to a mild, natural, organic
seaweed-based fertilizer added to the water once every three months
during the summer. The Kirstenbosch plants also get a dose of inorganic
2:3:4 in the spring.
The cotyledons may last for up to two years in cultivation. They
become erect and expand to a length of 27-35 mm and the permanent
leaves will then become visible between them. They are always opposite
to the cotyledons and it is these two leaves that the plant retains
for life. The permanent leaves grow rapidly, soon overtaking the
cotyledons. They are upright at first, becoming erectly spreading
after 8-12 weeks and eventually diverging. Between the two leaves
another pair of what appear to be leaves will appear. These are
the cotyledonary buds, also situated opposite the cotyledons. They
gradually become swollen and keeled and from here onwards, the peculiar
growth habit begins. These cotyledonary buds are in fact axillary
buds whose apical growth stops, causing the death of the growing
tip. Now, instead of apical growth the buds gradually broaden, eventually
merging. The meristematic tissue at the base of the buds now grows
sideways, together with the meristematic tissue on the outer sides
of the leaf, which causes the leaf groove to deepen and causes the
characteristic obconical growth of the stem apex. This growth occurs
annually during the warmer months and is visible in concentric rings.
Thus age can be roughly estimated by counting these rings, analogous
to the growth rings of a tree.
Welwitschia is relatively disease-free, except during its
first year or so when it should be watered with a fungicide. They
are prone to attack by woolly aphid, but this can be controlled
with an insecticide like Malasol. Caterpillars have also been caught
on the leaves of the Kirstenbosch plants.
- VAN JAARSVELD, E. 1990. The cultivation and care of Welwitschia
mirabilis: the extraordinary caudiciform from the Namib Desert.
Aloe 27; 69-82.
- VAN JAARSVELD, E. 2000. Welwitschia mirabilis. Veld &
Flora 86: 176-179.
- VAN JAARSVELD, E. 1992. Welwitschia mirabilis in cultivation
at Kirstenbosch. Veld & Flora 78: 118-120.
- CRAVEN, P. & MARAIS, C. 1992. Damaraland Flora. Gamsberg,
Macmillan, Windhoek, Namibia.
- CRAVEN, P. & MARAIS, C. 1986. Namib Flora. Gamsberg,
Macmillan, Windhoek, Namibia.
Kirstenbosch National Botanical Garden