Welwitschia is a monotypic gymnosperm genus, comprising solely the distinctive Welwitschia mirabilis, endemic to the Namib desert within Namibia and Angola.
The plant is commonly known simply as welwitschia in English, but the name tree tumbo is also used. It is called kharos or khurub in Nama, tweeblaarkanniedood in Afrikaans, nyanka in Damara, and onyanga in Herero.
Welwitschia is the only living genus of the family Welwitschiaceae and order Welwitschiales in the division Gnetophyta, which contains three genera altogether. Informal sources commonly refer to the plant as a "living fossil"