Has Two Leaves. Dies Hard.

One of the truisms (and clichés) we hear about desert environments is that their resident life forms are specialized to survive and even thrive under difficult conditions. It isn’t generally difficult to imagine how a desert organism’s shape and behaviours make sense insofar as they contribute to its survival; for instance, it is intuitive to us that a cactus stores water when available and use the stores to sustain itself during dryer periods, or that a desert animal might be active only at night when temperatures are more moderate.

Imagine now that you are visiting a faraway desert and encounter a giant green heap of leaves on the ground, perhaps approaching your own stature. Clearly it is a plant, but what is it, how does it come to appear this way and how is it possibly well-adapted? These may be some of the questions that outside explorers first asked when encountering an unconventional plant in the coastal Namib Desert of southwest Africa. Though it already carried names in the indigenous Nama, Damara and Herero languages, it would be given the name of Welwitschia mirabilis in honour of the Austrian botanist Friedrich Welwitsch who made it known to the outside world. And indeed the plant is as wonderful as the scientific species name of “mirabilis” means to tell us, but we need to look at the different life stages of the Welwitschia (pronounced “Vel-vi-chee-a”) to understand.


After germination and initial establishment, a Welwitschia looks like this, with two tough, strap-like leaves opposite each other and growing out of what appears to be a narrow wooden stump. The stump is in fact the original stem of the plant, the top tissue of which simply stops growing and dies. The leaves continue growing out of the fringes of the stem, in fact continuously over the life of the plant.


Theoretically the leaves could become many metres in length but the wind tosses them about as they grow and causes the tips to fray and wear. The fraying also splits the leaves from the tips down towards the base, giving the impression that the plant has multiple leaves when in fact it still has but two.


Meanwhile, the base out of which the leaves grow continues to grow in size. Presumably due to idiosyncrasies of local conditions and circumstances, the base can become quite distorted over time, causing the leaves to also grow in a distorted fashion, contributing further to their splitting and making them appear to grow out of multiple points of origin. Over time, Welwitschia can become quite a morass described by some as a ‘desert octopus’!