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> Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants)
> Gymnospermae >
Coniferophyta (conifers) > Gnetales
Welwitschia mirabilis in the Namib Desert.
[photos H. Robertson ©]
Gymnosperms are normally tree-like plants but the
Welwitschia is remarkable in being a gymnosperm that has developed a prostrate
growth form and deep root system apparently to survive desert conditions. It is
also interesting in that each plant has only two leaves, which grow
continuously. While the leaf is growing from the base, the end is becoming
frayed and dried so each leaf is kept to a reasonable length. Carbon
dating has revealed that plants can grow to at least 600 years old.
Distribution and habitat
Grows in the extremely arid desert region extending from
the Kuiseb River in Namibia to Cape Negro in Angola.