Welwitschiaceae
The family Welwitschiaceae contains the monotypic genus Welwitschia.
The type species, Welwitschia mirabilis, from South-West Africa has a short, central, unbranched, woody caudex up to 3ft in diameter from which grows a single pair of persistent tough, leathery cotyledons. These grow longer with time, from the meristem at their junction with the caudex. The ends of the leaves fray in the desert sandstorms and split lengthwise along the leaf veins, but otherwise are of indefinite length. No other leaves are ever produced. A long tapering taproot extracts scarce moisture from deep under the plant.
The plants are dioecious, bearing inflorescences with clusters of male and female cones on separate plants. Pollen is distributed by wind and by a variety of insects that feed on it. Individual plants are slow growing and may be thousands of years old. Welwitschia mirabilis is thought to be a representative of an ancient group of plants with primitive characteristics.
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Plant Families with Succulent Species