• North American
  • Although there has been a remarkable evolutionary and morphologic diversification in North American Cirsium , it has not been accompanied by very much divergence in the base sequences of genes commonly used to elucidate phylogenetic relationships. (efloras.org)
  • This suggests either that the diversification has been very rapid or that genetic markers in North American Cirsium mutate more slowly than in most other lineages. (efloras.org)
  • Chromosomal diversification has accompanied the morphologic radiation of North American Cirsium . (efloras.org)