Monday, 31 May 2010

Welwitschia - living fossils of Namibia

It is rather amazing that the Welwitschia has survived all these years; it grows in one of the most inhospitable places in the world, collects water only from dew and as it can reach over 2,000 years in age it is often sought after by illegal plant collectors.  All in all, its survival does not look great.

Welwitschia are found in the deserts of Namibia and Angola, the plant population in Angola is fairing better as landmines prevent over zealous collectors.  Each plant is made up of only two leaves, which split as the leaves grow, making it very difficult to discern where the leaves begin, believe me, I have tried.  On these leaves there are approximately 22,000 stomata, small holes, per square cm (upper and lower sides) which are used in the exchange of gases during photosynthesis.  These are also used to absorb moisture, in the form of dew, and during wet and foggy conditions these stomata remain open, unlike the stomata on the leaves of its counterparts.  The species is also dioecious, meaning that each plant is either male or female, and insects are used for cross fertilisation.  The plant ingeniously attracts specific insects to both plants by a delicious nectar that these insects find very attractive.

All in all a very weird plant.  The big Welwitschia (pictured above) stands at 1.4m high and is aged at 1,500 yrs old, however there are some experts that claim it to be twice that age.  It is a plant which is well worth the visit, permits required along with a sense of adventure.  And remember to take water with you.

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