Welwitschia The sole genus, with only one species (W. mirabilis) of the remarkable gymnosperm family Welwitschiaceae (related to Ephedraceae (see EPHEDRA) and Gnetaceae (see GNETUM) of the deserts of south-western Africa. It has a barrel-like stem with a deep tap root, bearing on its rim big, tattering, strap-like leaves, and flowers that are small, dioecious, and covered by bracts, with the single, erect ovule within the perianth tube of the female flower.

welwitschia (tumboa) Plant that grows in the sandy regions of sw Africa. It produces only two leathery leaves that split into many ribbon-like strands up to 1.2–1.8m (4–6ft) long. Welwitschia may live up to 2000 years. Cone clusters – actually small flower spikes – are borne each year on both male and female plants. Division Gnetophyta; species Welwitschia mirabilis.