Welwitschia mirabilis in Namib Naukluft Park

Welwitschia mirabilis in Namib Naukluft Park

The Namib Desert is probably the oldest desert on Earth.  Because of the quirks of plate tectonics and geology, it has been the same hot arid landscape since West Gondwanaland shifted to its present position along the Tropic of Capricorn nearly 130 million years ago!  Some of the regional plants and animals of the Namib Desert have had a very long time to adapt to the baking sun and shifting sands of West Africa’s Skeleton Coast.  The sandswimming (and misnamed) golden mole is a prime example of the strange animals which live in the Namib, but an even weirder organism is the ancient monotypic plant Welwitschia mirabilis.  As the sole member of its own genus, family, and order, the plant is a bizarre evolutionary loner.  This suits the strange plant well–since some specimens exist in stupendous isolation, far from all other plants in the midst of great desolate plains.  There, single plants can live for up to two millennia or longer, in environs which would swiftly kill most other living things.  Their distinctive appearance—a huge convoluted heap of withered ancient leaves of immense length—is a sort of trademark of the Namib Desert.

The coat of arms of Namibia features one at the bottom

The coat of arms of Namibia features one at the bottom

But Welwitschia mirabilis is even stranger than its bizarre appearance and lifestyle first indicate.  It is one of the last three surviving gnetales—a division of the ancient gymnosperms (which also include conifers, cycads, and ginkgos).  Botanists are still arguing about the exact taxonomy of the gnetales, but they seem to have evolved in the Jurassic era.  As the dinosaurs came and went, as the seas rose and fell and great ice sheets carved the world and then melted, welwitschia has sat in its inhospitable corner of the globe and quietly prospered (even as all of its close relatives died away).

A young Welwitschia

A young Welwitschia

Each welwitschia has only two strap-like leaves which grow continuously over its long life.  As the desert winds rip into the plant, these leaves become shredded into different ribbons and segments, but they remain the same two leaves—growing longer and longer like some tangled Rapunzel.  The all-important taproot of the plants is just as strange—a huge shallow water collecting disk which has approximately the same radius as the length of the leaves.  Each plant has its own gender and they are pollinated by flies and desert Hemiptera (true bugs).

Welwitschia mirabilis with a dangerous African animal species

Welwitschia mirabilis with a dangerous African animal species

Oddly enough, in our world of mass extinction, welwitschia plants are doing fine.  Although collectors have gathered some, there are still plenty left in places where people do not want to go. The plants in tumultuous Angola are better protected than those in democratic, ecologically-minded Namibia (simply because Angola’s many wars have left vast, unmapped zones of landmines where people never venture).  The welwitschia’s hermit-like asceticism is a very good strategy in our hedonistic Anthropocene world.

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