GNETOPHYTE

any member of the division Gnetophyta, a small group of vascular gymnospermous plants that are represented by three genera: Ephedra, Gnetum, and Welwitschia. There are about 35 species in the genus Ephedra, 30 or more in Gnetum, but only one in Welwitschia. The three genera exhibit their great diversity in the immense variety of form and size among the various species. Ernest M. Gifford Additional reading A general treatment of the gnetophytes can be found in Peter H. Raven, Ray F. Evert, and Susan E. Eichhorn, Biology of Plants, 4th ed. (1986). Chris H. Bornman, Welwitschia: Paradox of a Parched Paradise (1978), is a brief study of Welwitschia mirabilis.