| Photo Information |
Copyright: antoine perroud (toine74)
![Silver Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 41 W: 24 N: 72]](http://i1.trekearth.com/misc/s-s-g.gif) (557) |
| Genre: Places |
| Medium: Color |
| Date Taken: 2005-05-13 |
| Categories: Nature |
| Camera: Minolta Dynax 7D, 24-50mm f4 |
| Exposure: f/8, 1/1000 seconds |
| Photo Version: Original Version |
| Date Submitted: 2007-05-15 9:17 |
| Viewed: 895 |
| Points: 2 |
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| [Note Guidelines] Photographer's Note |
"Welwitschia is a monotypic genus of gymnosperm plant, comprised solely of the very distinct Welwitschia mirabilis. It is the only genus of the family Welwitschiaceae, in the order Welwitschiales, in the division Gnetophyta. The plant is considered a living fossil.
This is a desert plant which grows from a short, thick trunk, with only two leaves that continuously grow from their base, and a long, thick taproot. After germination, the cotyledons grow to 25-35 mm in length, and are followed shortly afterwards by the appearance of the two permanent leaves. These leaves are produced opposite that of the cotyledons, and continue to grow throughout the life of the plant, eventually growing to 2-4 m long and usually becoming split into several strap-shaped sections. After these appear, two cotyledonary buds appear; in these, the growing tip dies, causing elongation of the buds. Growth continues sideways, which forms the obconical growth of the stem. The species is dioecious, with separate male and female plants.
The age of the plants is difficult to assess, but it is believed that they are very long-lived, possibly living 1000 years or more. Some individuals may be more than 2000 years old.
The plant is thought to absorb water through peculiar structures on its leaves, harvesting moisture from the dew that comes into the desert every night. Named after Dr. Friedrich Welwitsch who discovered it in 1860, it is generally considered to be one of the oddest plants in existence. Although considered endangered due to its very slow growth and the fact that older plants are desired by collectors, a fair number of plants exist in the wild. The plants living in Angola are generally considered to be better protected than the plants in Namibia, owing to the relatively high concentration of landmines in Angola, which keep collectors away.
Welwitschia mirabilis est la seule espèce du genre Welwitschia et de la famille des Welwitschiacées. Cette plante très particulière des déserts côtiers de Namibie a été nommée en l'honneur du Dr. Friedrich Welwitsch qui l'a découverte en 1860. Elle est constituée de deux grandes feuilles linéaires qui croissent de façon indéfinie dans des sens opposés et dont les extrémités se dilacèrent. Sa longévité est considérable : certains spécimens observés ont entre 1000 et 2000 ans.
quote from Wikipedia |
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