These often very unusual plants are from ancient plant families believed to be relatives of cycads, conifers and ginkgoes. The gnetophyta are comprised of three basic types of gymnosperms:
Gnetum: A genus of tropical plants with highly variable morphologies, some trees and some vines.
Welwitschia: The genus is comprised of single desert species, an untidy-looking plant which is essential a form of foliage growing like creepers. The growth pattern based on extensions of dicots, a type of shoot. This gives the plant a low vertical profile and protection from hot winds.
Ephedra: The species from which ephedrine is derived. There are about 50 separate species in this genus. These are shrubs, usually growing naturally in dry climates on all continents except Australia.