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Welwitschia mirabilis
Scientific classification
Families & genera

see text

The Gnetophytes are a group of seed plants with three genera. Their evolutionary relationships are unclear, but it is now clear that they are related to each other.[1]

The three genera are:

By looking at the structure of these organisms (morphology) and the DNA (molecular taxonomy), scientists have found that Gnetum and Welwitschia are more closely related to each other than to Ephedra.[2][3][4][5]


  1. Peter R. Crane, Patrick Herendeen and Else Marie Friis (2004). "Fossils and plant phylogeny". American Journal of Botany 91: 1683–1699. doi:10.3732/ajb.91.10.1683 . 
  2. Bowe L.M; Coat G. and dePamphilis C.W. (2000). "Phylogeny of seed plants based on all three genomic compartments: extant gymnosperms are monophyletic and Gnetales’ closest relatives are conifers". Proceedings of the National Academy of Science 97: 4092–4097. doi:10.1073/pnas.97.8.4092 . 
  3. Gugerli F. (2001). "The evolutionary split of Pinaceae from other conifers: evidence from an intron loss and a multigene phylogeny". Molecular Phylogeny and Evolution 21 (2): 167–175. doi:10.1006/mpev.2001.1004 . PMID 11697913 . 
  4. Rai H.S. (2008). "Inference of higher-order conifer relationships from a multi-locus plastid data set". Botany 86: 658–669. doi:10.1139/B08-062 . 
  5. Ickert-Bond S.M; C. Rydin and S.S. Renner (2009). "A fossil-calibrated relaxed clock for Ephedra indicates an Oligocene age for the divergence of Asian and New World clades, and Miocene dispersal into South America". Journal of Systematics and Evolution 47: 444-456.