Gnetales
Quick Summary
The order Gnetales is a small group of gymnospermous vascular plants that includes three living genera: Ephedra, Gnetum, and Welwitschia. These genera display significant diversity in form and size.1
- Ephedra: Primarily branched shrubs or small trees, some are vinelike. They are found in dry, cool regions worldwide, including high altitudes. An Ephedra species is the source of ephedrine, a decongestant.1
- Gnetum: Mostly lianas that climb in tropical rainforests, though some are trees. They have large leaves resembling those of flowering plants, and their seeds and young leaves are edible.1
- Welwitschia: A unique desert plant found in southwestern Africa, characterized by only two large, permanent leaves that split with age. It has a deep taproot to access water.1
A key feature distinguishing gnetophytes from other gymnosperms is the presence of vessels in their xylem, a characteristic also found in flowering plants. This, along with other reproductive specializations, has led to discussions about their evolutionary relationship to angiosperms, though modern research suggests they did not directly evolve from gnetophytes.1234
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