, Volume 42, Issue 3, pp 197–211

Cladistics of the Spermatophyta

  • Henry Loconte
  • Dennis W. Stevenson

DOI: 10.2307/2807216

Cite this article as:
Loconte, H. & Stevenson, D.W. Brittonia (1990) 42: 197. doi:10.2307/2807216


A cladistic interpretation of seed plant phylogeny is presented that supports the traditional morphological hypothesis: [Cycadales-(Ginkgoales-(Coniferales-(Gnetales-Angiosperms)))]. Gnetales and Angiosperms are supported as sister groups of theAnaspermae. A sister-group relationship between Coniferales and Ginkgoales represents a paraphyletic group, because Coniferales and Anaspermae share a common ancestry (Mesospermae). Ginkgoales and Mesospermae are sister groups of theCladospermae. Cycadales are supported as the most archaic Spermatophyta.A posteriori consideration of fossil taxa supports the conclusion that data from the fossil record are useful for confirming plesiomorphies of extant taxa. Fossil taxa with apomorphic character states are discussed as biasing for superficial accelerated transformations, which are probably unacceptable from the standpoint of morphological homology.

Copyright information

© the New York Botanical Garden 1990

Authors and Affiliations

  • Henry Loconte
    • 1
  • Dennis W. Stevenson
    • 1
  1. 1.New York Botanical GardenBronx

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