Description:

• Plant dioecious; stem woody, unbranched (closed system of growth), broadly obconic or turbinate, concave on top, outer covering corky; taproot elongated, branching near apex
• Leaves produced from subcircular groove around rim of crater-like apex of plant, parallel-veined, persistent, growing from base
• Inflorescences arising from floriferous cushions above and sometimes also below insertion of leaf
• Flowers unisexual (male pseudo-bisexual but functionally unisexual), borne singly in axils of scales forming small cones
• Male flowers: perianth segments 4, in 2 whorls; stamens 6, with filaments connate at base; anthers 3-thecate, dehiscing by 3 slits at summit, pollen grains ellipsoidal with ± 20 longitudinal ridges; ovule single, abortive, with integument produced into a style-like tubular structure and expanded at apex into a stigma-like, papillose disc
• Female flowers: perianth segments 2, navicular, united along margins to enclose the ovule, flattened, with wings developing along keels; ovule with single integument produced into style-like tubular structure which eventually is exserted, widened and lobed at apex
• Seeds winged; cotyledons 2, endospermous

Classification Notes:

• The Standing Committee on the Stabilization of Specific Names decided (Schubert 1975) that the specific name Welwitschia mirabilis Hook.f. takes priority over W. bainesii (Hook.f.) Carr. on the grounds that the latter was based on the provisional name Tumboa bainesii Hook.f.

Nomenclature:

• Welwitschia Hook.f.
  • Hooker: 71 (1862)
  • Pearson: 1 (1933)
  • Verdoorn: 49 (1966)
  • Friedrich-Holzhammer: 1 (1967)
  • Kubitzki: 390 (1990)
  • Von Breitenbach & Von Breitenbach: 211 (1992)

Distribution & Notes:

• Southern Africa: Species 1: Welwitschia mirabilis Hook.f., confined to the Namib desert in Namibia and Angola