Gnetophytes

Gnetophytes prefer subtropical to tropical regions. Consisting of 71 species, this division only contains 3 genera, Ephedra, Gnetum, Welwitchia. The vessels in the xylem of the vascular tissue and the double fertilization that occurs during reproduction distinguishes these plants from the other gymnosperms. Gnetophytes also have the closest evolutionary relationship with the flowering plants, the angiosperms.

Welwitchia mirabilis, is a uniquely shaped plant found only in the Namib and Mossamedes deserts of Africa. This plant can live up to 1,500 years. A peculiarity of this species can be seen during fertilization. The egg inside the large cone migrates to the pollen tube that has been transported into the vicinity, instead of the pollen migrating to the egg. Unfortunately, only about 20 to 200 seeds are produced from the 10,000 to 20,000 ovules in the cone because of sterility and insect infestation.