How does Welwitschia survive in the dry Namib Desert?

Welwitschia mirabilis survives in the arid Namib Desert, where annual rainfall is often less than 25 mm (1 inch), through several specialized adaptations:

• Deep Root System: The plant possesses a deep taproot that may extend 1.5 meters (about 5 feet) or more underground, likely allowing it to access water sources unavailable to other desert vegetation.1
• Fog Absorption: It is hypothesized that Welwitschia may absorb water from the desert's frequent morning fog through its leaves, though this process remains unproven.1
• Leaf Cooling: The plant maintains its two permanent, straplike leaves throughout its life. During the day, it takes up carbon dioxide through its stomata, which results in significant water loss through transpiration; this process is thought to help cool the leaf surface in the extreme desert heat.1

As a unique gnetophyte, Welwitschia is highly specialized for its environment and is now protected by law due to its rarity and historical over-collection.12