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Welwitschia
Welwitschia mirabilis
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A 'living fossil' gymnosperm endemic to the Namib Desert. It produces only two leaves in its entire lifetime, which continue growing for years and become tattered. Individuals over 1,000β2,000 years old exist. A monotypic lineage (1 family, 1 genus, 1 species).
Identification Points
- βTwo long, coriaceous leaves spread along the ground and become tattered over time
- βThe stem is short and inversely conical, with very little above ground
- βCone-like male and female strobili emerge from the stem apex (gymnosperm)
Habitat
Namib Desert and southern Angola (in greenhouses and botanical gardens in Japan)
Season
Year-round (evergreen)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Leaf arrangement
Opposite
Leaf type
Simple
Venation
Parallel
Leaf margin
Entire
Leaf shape
Linear
Petal fusion
No petals
Stipules
Absent
Ovary position
Superior
Plant sex
Dioecious
Phylogenetic Positionγ¦γ§γ«γ¦γ£γγγ’η§ β
Phylogenetic Position
Gymnosperms > Gnetophytes > Gnetales > Welwitschiaceae
Divergence Era
Jurassic to Cretaceous (ca. 130 million years ago)
Evolution Notes
Welwitschiaceae is a member of Gnetales that diverged approximately 130 million years ago, evolving a unique morphology adapted to extreme desert aridity. The stomatal structure of the leaves is also specialized for absorbing moisture from fog.
View on evolution timeline βSources & References
AI-generated, needs verification