After Earle, 2002- and Donoghue, 1996-1998

<==o Gnetales Luerss. 1879
   |--o Ephedraceae Dumortier (Mormon Tea or Joint Fir family)
   |  `-- Ephedra Linnaeus 1753 ()? [37]
   `--+--o Welwitschiaceae Markgraf.
      |  `-- Welwitschia mirabilis Hooker 1863 (welwitchia)
      `--o Gnetaceae Lindley
         `-- Gnetum Linnaeus ()? [32]

Reference(s):