Gardening

Welwitschia mirabilis: A Plant Oddity

“Gesundheit!”

That’s what I said when I first heard the name of this plant. Welwitschia mirabilis, that’s not a name! It’s often known as Welwitschia but it may be called “tree tumbo” in English, but that’s about it.

Never heard of it? That’s normal: it’s not a plant you’d normally have in your garden or in a pot at home. It’s more of a plant curiosity, a unique and fascinating plant for curious gardeners.

Unique in the World

Discovered in the 1800s, this plant only lives in a very small part of the world: the coastal deserts of Namibia and Angola. Plan your next vacation in Africa accordingly!

Source : Thomas Schoch

W. mirabilis is the only species of its genus, family and even order. When I tell you it’s like no other, it’s true! It has no close relatives and nothing ordinary about it.

An Impressive Plant… and a Curious One Too

But let’s start at the beginning: the start of the plant. Two leaves emerge from the earth: these are the cotyledons. Then come two more leaves that will grow, and grow, and grow, and never stop, forever. What? Yes, you see: this plant will only make two true leaves in its lifetime, and they’ll grow ad infinitum. It’s the only species in the plant world that produces this kind of leaf, which is never replaced, and grows continuously.

© orxy/Fotolia

Of course, with the weather, the leaves eventually split, become damaged and dry out, and it’s not particularly pretty. As a result, it’s hard to spot a specimen with leaves over four meters long. Fortunately, their thickness, around a centimetre and a half (1/2″), provides a minimum of protection.

If you’ve read the recent article on why plants lose their leaves, you may remember that I mentioned the lifespan of leaves. Are leaves immortal? Well, since they grow continuously, yes. But leaf cells have a life expectancy of ten years or so. See the trick? Because the leaf grows continuously, it’s constantly making new, young, healthy cells!

Photo: Jonathan Basson

But don’t think that leaf debris is useless! Living in the desert, this debris would serve both as mulch, to keep a little moisture in the soil, and as fertilizer for the plant.

A short trunk forms a kind of spiral under these two leaves, and a large taproot (like a carrot) anchors it to the ground. The oldest specimens are about one and a half meters high and eight meters in diameter. What does “old” mean to Miss W.? Scientists estimate their lifespan at some… 2000 years! If plants could talk, she’d have some stories to tell…!

An Original Conifer Reproduction

Oh, yes… I forgot to mention this detail: this plant is a conifer…! Not quite the kind of tree with needles we know, eh!

Miss Welwitschia, then, is dioecious, i.e. there are male and female individuals. So far, so good. But here’s where it gets a bit unusual: the pollinator isn’t the wind, as with most other conifers, but insects. It’s one of the few conifers to produce nutritious nectar to attract pollinators.

Plant femelle. Source: Wikipedia

Since conifers have no flowers, nectar is found in the cones. Usually, these are either male or female… but it’s not so simple with W. mirabilis. Female cones use their ovaries to produce nectar. Male cones, on the other hand, usually lack the necessary nectar-making organs. But if pollen is to be transported from the male to the female plant, it has to be! Male cones have therefore developed sterile ovaries that produce nectar.

Male cone. Photo: KLEIN Benjamin

In short, it’s ALMOST a hermaphrodite, like many flowering plants, but both individuals are necessary for reproduction, since only the female can produce ovules (seeds) in her ovaries. The seeds will therefore grow on the cones of the female individuals and will be round and flat, like a pine or parsnip seed, to be dispersed by the wind.

Seed. Photo: Amada44

Maybe I’m getting too carried away with the details, but you know… when it comes to (plant) sex , it just gets to me!

An Oasis in the Desert

This plant alone creates a microclimate where animals can take refuge, feed and protect themselves. Remember, we’re in the desert and, apart from morning dew and coastal fog, little water is accessible. Miss W. could absorb water through her leaves and roots, making her gorged enough to be chewed on by several species of mammal (zebra, rhino, antelope) in dry periods. It also serves as a cool spot for bird nests (especially for Gray’s Lark) and as shelter for snakes, lizards, insects, etc.

Remember the water truce in the remake of The Jungle Book? During a particularly severe drought, all animals are welcome at the water source. Prey and predators live in harmony for this brief moment, because water is too vital a resource for everyone: without water, there is no life.

It’s a beautiful, logical concept: if all herbivores die of thirst, then carnivores will die of hunger, water or no water! It’s nice to imagine a Miss W. full of life of all kinds, full of peace and harmony…

But that’s not how life works!

In real life, the lion will ambush the zebra near the pond in its territory and catch it drinking. But since zebras live in groups, one or two deaths are no big deal. The same goes for W. mirabilis. If a venomous snake is already hiding there, the lark won’t nest there!

In short, if you’ve had a pretty picture worthy of The Jungle Book following my evocation of all the life that uses this plant, it’s great, but not too realistic!

A Miss W. at Home?

Although relatively numerous throughout its range, this plant is protected. Collectors have led to poaching of old plants, 4×4 ecotourism vehicles sometimes break and kill plants, and a fungus attacking fruit and seeds is a cause for concern.

If you absolutely must have one at home, I’m happy to say that seed trading is permitted! Be careful, however, not to buy from a dodgy supplier, as seeds from plants in the wild run a high risk of being contaminated by the fungus Aspergillus niger, a fairly common black mould found on fruit and vegetables that will cause your seedling to die after germination.

In short, if you’re a collector of rare and strange plants, check your sources for fungus-free seeds. A quick search on the Net turned up several sites that sell them for around $15 a seed, but since the provenance isn’t indicated, I’d ask questions about the supplier. Were they harvested in the wild or in a botanical garden? When were they harvested? How were they harvested? What do you think?

Potted specimen at the Huntington Library and botanical garden.Photo: JayWalsh

For germination at home, it seems simple enough: two weeks of humidity, warmth, sun… It’s the aftermath that would scare me, as I struggle to get enough light for my “normal” plants! If you give it a try, I’d love to hear from you!

Well, I hope I’ve piqued your curiosity with this amazing plant, Welwitschia mirabilis. Even though the chances of you having one are pretty slim, are you interested in the “strange and mysterious plants of the world”? Who knows, it just might make for an interesting Halloween series this year!

Audrey Martel is a biologist who graduated from the University of Montreal. After more than ten years in the field of scientific animation, notably for Parks Canada and the Granby Zoo, she joined Nature Conservancy of Canada to take up new challenges in scientific writing. She then moved into marketing and joined Leo Studio. Full of life and always up for a giggle, or the discovery of a new edible plant, she never abandoned her love for nature and writes articles for both Nature sauvage and the Laidback Gardener.

5 comments on “Welwitschia mirabilis: A Plant Oddity

  1. That think is just too weird all the way around!

  2. Shauna Dobbie

    Such a strange plant! Very cool.

  3. Diane Sanders

    This is fascinating! Thanks. What a good read!

  4. Wonderful post. My local university has a botanic garden and I am definitely going
    to see of they have a specimen. I was particularly struck by their longevity!

  5. When I was in Namibia, I visited a sites where there were many of the plants, and often had the area around the plants marked off to avoid damage
    DMPT

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