If you need an accessible version of this item please contact JSTOR User Support

Cladistics of the Spermatophyta

Henry Loconte and Dennis W. Stevenson
Brittonia
Vol. 42, No. 3 (Jul. - Sep., 1990), pp. 197-211
Published by: Springer on behalf of the New York Botanical Garden Press
Stable URL: http://www.jstor.org/stable/2807216
Page Count: 15
  • Download PDF
  • Cite this Item

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support
Cladistics of the Spermatophyta
Preview not available

Abstract

A cladistic interpretation of seed plant phylogeny is presented that supports the traditional morphological hypothesis: [Cycadales-(Ginkgoales-(Confiferales-(Gnetales-Angiosperms)))]. Gnetales and Angiosperms are supported as sister groups of the Anaspermae. 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 the Cladospermae. 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.

Page Thumbnails

  • Thumbnail: Page 
[197]
    [197]
  • Thumbnail: Page 
198
    198
  • Thumbnail: Page 
199
    199
  • Thumbnail: Page 
200
    200
  • Thumbnail: Page 
201
    201
  • Thumbnail: Page 
202
    202
  • Thumbnail: Page 
203
    203
  • Thumbnail: Page 
204
    204
  • Thumbnail: Page 
205
    205
  • Thumbnail: Page 
206
    206
  • Thumbnail: Page 
207
    207
  • Thumbnail: Page 
208
    208
  • Thumbnail: Page 
209
    209
  • Thumbnail: Page 
210
    210
  • Thumbnail: Page 
211
    211