Monotypic gymnosperm genera

Welwitschia is a monotypic genus of gnetophytes containing only the species Welwitschia mirabilis. It is named after the Austrian botanist Friedrich Welwitsch, who documented the plant in the 1850s. In common use, it is sometimes referred to as the tree tumbo. It is native to Angola and Namibia, where it grows in the extreme conditions of the Namib desert, tolerating high heat and low precipitation. Welwitschia is the only living genus of the family Welwitschiaceae and order Welwitschiales, and is one of three extant genera of gnetophytes, alongside Gnetum and Ephedra.

Stangeria eriopus is a cycad endemic to southern Africa. It is the sole species in the genus Stangeria.

Microcycas is a genus of cycads in the family Zamiaceae containing only one species, Microcycas calocoma, endemic to a small area in western Cuba in Pinar del Río Province. It is estimated that there are 50-249 mature individuals left in the wild.