A remarkable and probably artificial division of gymnosperms that comprises only the Gnetales. There are 3 constituent genera, embracing trees, shrubs, and lianes (Ephedra and Gnetum), and even turnip-like plants (Welwitschia). Possible fossil material of the group is known from the early Permian, and there is also some fossil pollen from the Tertiary. With such a scant record it is not surprising that the evolutionary relationships of Gnetales remain unclear.
Subjects: Plant Sciences and Forestry.