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. ^[1] Photo of a Welwitschia mirabilis, taken in the Ugab River valley in Namibia in October 2004 by Muriel Gottrop. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... For other uses, see Plant (disambiguation). ... taxa: Gnetales Welwitschiales Ephedrales The plant division Gnetophyta or gnetophytes comprise three related families of woody plants grouped in the gymnosperms, a paraphyletic group of seed plant divisions. ... taxa: Gnetales Welwitschiales Ephedrales The plant division Gnetophyta or gnetophytes comprise three related families of woody plants grouped in the gymnosperms, a paraphyletic group of seed plant divisions. ... This article does not cite any references or sources. ... Joseph Dalton Hooker Joseph Dalton Hooker Sir Joseph Dalton Hooker, GCSI, OM, FRS, MD (June 30, 1817 – December 10, 1911) was an English botanist and traveller. ... For other uses, see Genus (disambiguation). ... Divisions Pinophyta (or Coniferophyta) - Conifers Ginkgophyta - Ginkgo Cycadophyta - Cycads Gnetophyta - Gnetum, Ephedra, Welwitschia The gymnosperms (Gymnospermae) are a group of spermatophyte seed-bearing plants with ovules on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone-like structures. ... For other uses, see Plant (disambiguation). ... taxa: Gnetales Welwitschiales Ephedrales The plant division Gnetophyta or gnetophytes comprise three related families of woody plants grouped in the gymnosperms, a paraphyletic group of seed plant divisions. ... This article or section does not adequately cite its references or sources. ...

Female plant

The geographic distribution of Welwitschia mirabilis is limited to south-west Africa, specifically, to the Namib desert within the two countries, Namibia and Angola. It 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 two permanent leaves. These leaves are produced opposite of the cotyledons, and continue to grow throughout the entire life of the plant. They eventually grow to a length of 2-4 m and usually become split into several strap-shaped sections, thus sometimes disguising the origin from only two leaves. 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. Fertilization, that is, the transfer of the pollen from the male to the female flowers, is apparently carried out by insects that are attracted by nectar produced on both male and female flowers.^[2] Image File history File links Welwitschia-mirabilis-female. ... Image File history File links Welwitschia-mirabilis-female. ... A world map showing the continent of Africa Africa is the worlds second-largest and second most-populous continent, after Asia. ... Dune 7, one of the highest sand dunes in the world (ca. ... Look up foliage in Wiktionary, the free dictionary. ... This article is about the plant root system. ... cotyledon in formation before the accumulation of the reserves seen at Judas-tree (Cercis siliquastrum) Comparison of a monocot and dicot sprouting A cotyledon (Greek: κοτυληδών) is a significant part of the embryo within the seed of a plant. ... Close-up of an Echinopsis spachiana flower, showing both carpels and stamen, making it a complete flower. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ...

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 largest known Welwitschia, nicknamed "The Big Welwitschia", stands 1.4 m tall and is over 4 m in diameter.

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. As a further adaptation to the arid conditions and hot daytime temperatures in its environment, and as the only gymnosperm species known to do so, W. mirabilis uses the crassulacean acid metabolism (CAM) pathway for carbon fixation in photosynthesis.^[3] 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 despite the fact that older plants are often sought 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 ^{[citation needed]}. Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1600 × 1200 pixel, file size: 355 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1600 × 1200 pixel, file size: 355 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Divisions Pinophyta (or Coniferophyta) - Conifers Ginkgophyta - Ginkgo Cycadophyta - Cycads Gnetophyta - Gnetum, Ephedra, Welwitschia The gymnosperms (Gymnospermae) are a group of spermatophyte seed-bearing plants with ovules on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone-like structures. ... Crassulacean Acid Metabolism (CAM) is a carbon fixation pathway in some photosynthetic plants. ... Dr. Friedrich Welwitsch (1806 – October 20, 1872) was an Austrian explorer and botanist. ... “Minefield” redirects here. ...

The species grows readily from seed, which may be purchased from specialty seed dealers. The seed must be kept moist for the first couple of weeks and exposed to as much heat and light as possible during this time. Seeds collected from the wild are often heavily contaminated with spores of Aspergillus niger, which causes them to rot shortly after they germinate. Seeds from the Kirstenbosch National Botanical Garden in Cape Town, South Africa, or other cultivated sources are much cleaner and less likely to rot. ^{[citation needed]} A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ... ... View roughly to the north from Kirstenbosch. ... Nickname: Motto: Spes Bona (Latin for Good Hope) Location of the City of Cape Town in Western Cape Province Coordinates: , Country Province Municipality City of Cape Town Metropolitan Municipality Founded 1652 Government [1]  - Type City council  - Mayor Helen Zille  - City manager Achmat Ebrahim Area  - City 2,499 km²  (964. ...

Heraldry

The plant figures as a charge in the national coat of arms of Namibia, as well as that of Westelike Rugby Subunie. In heraldry, a charge is an image occupying the field on an escutcheon (or shield). ... The Coat of Arms of Namibia is full of national symbols. ...

Links

List of Southern African indigenous trees SOUTHERN AFRICAN TREES, SHRUBS AND LIANES // Cyatheaceae Cyathea capensis (L.f. ...

References

1. ^ A. Lewington & E. Parker (1999). Ancient Trees: Trees that Live for a Thousand Years. Collins & Brown Ltd.. ISBN 1-85585-704-9. 
2. ^ Wetschnig W, Depisch B (1999). "Pollination biology of Welwitschia mirabilis HOOK. f. (Welwitschiaceae, Gnetopsida)". Phyton-Annales Rei Botanicae 39: 167. 
3. ^ von Willert DJ, Armbruster N, Drees T, Zaborowski M (2005). "Welwitschia mirabilis: CAM or not CAM - what is the answer?". Functional Plant Biology 32: 389. 

External links

Wikimedia Commons has media related to:

Welwitschia

• Gymnosperm database: Welwitschia
• Ecology & Evolutionary Biology Conservatory

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