Welwitschia – Welwitschis mirabilis
Natural History
|
Other Names: tumboa, n'tumbo (Angolan), tweeblaar-kanniedood (Afrikaans), !kharos (Nama, Damara), nyanka (Damara), khurub (Nama), onyanga (Herero), onion of the desert.
Distinctive Characteristics: Classified in a Family and Order all its own, the ancient Welwitschia is an odd, slow-growing species that seems to be evolutionarily stuck in prehistory, blurring the categorization between plant and tree. Named for the Austrian botanical explorer, Friedrich Welwitsch, it is uniquely adapted to limited areas in the harshest, most barren deserts in southern Africa, where almost no other flora can survive. The slow-growing Welwitschia is a dioecious, cone-bearing plant that has a subterranean woody trunk without annual growth rings. The majority of the trunk lives below the sandy ground, with a taproot system that can extend up to 30 ft. (9 m) deep. The crown barely surfaces mere inches above the ground, up to 2 ft. (0.6 m) tall, in curvaceous meanders like the jaws of a giant open clamshell. This crown, which sports either small male or female cones on flowery stalks, is sometimes barely visible, as it is buried beneath a pile of very unusual leaves. The Welwitschia grows two—and only two (unique in the plant kingdom)—very wide, leathery, ribbed, ribbony evergreen leaves, which can reach over 12 ft. (4 m) long, splitting, shredding, and fraying into a heaping, tangled mass, thick, hard and heavy, beaten by the harsh desert wind. It is through these leaves that minute pores absorb the majority of the tree's much-needed water from fog, in a region that barely receives 2 in. (5 cm) of rain a year. This hearty creature sits alone, looking something like an octopus that might slither across the sand and swallow you up whilst you're not looking. Distribution: Endemic to the Namib Desert in extremely limited patches in northwestern Namibia and southern Angola, within 30 miles inland, along the fog belt. Ecosystem: Arid and semi-arid desert and mopane savanna, in spread-out colonies, usually solitary. Maximum Age: Estimated to 1,500 years. Maximum Height and Girth: 6.5 ft. (2 m) in height; 27 ft. (8.2 m) in circumference as a pile of leaves. Animal Community: During drought, antelope, springbok, oryx, the endangered Hartmann's zebra, and rhino chew the leaves for their juice and spit out the tough fibers. It also acts as a shelter for birds, small reptiles and insects. Traditional Uses: The core, especially of the female plant, was eaten raw or baked in hot ashes. Threats and Conservation: Due to limited habitat, injury from off road vehicles, and a possible fungal pathogen that reduces female cone viability, it has been listed as Near Threatened by the IUCN Redlist. It is protected in some parks, and is being monitored. |
|
