La répartition des caractères dans la classification des Hamamelididae (Angiospermae)

Abstract

By using numerical methods, the authors have analyzed correlations between vegetative and floral characters within the Hamamelididae subclass to determine which characters prevail in the characterization of each group of families. The cophenetic correlation coefficient, topological difference, cluster membership divergence, subtree membership divergence, and partition membership divergence show very little congruence between the vegetative and floral characters; this is explained by the heterobathmic evolution of the characters. In Hamamelididae, characters that best delimit groups are also those which play an important role in phylogeny. When both vegetative and floral characters indicate the same delimitations, the classification can be considered natural. The best discriminating characters at the structural level are generally the most important in a cladistic analysis because of their variability. If the character correlation principle is considered, an exhaustive analysis of the classification can help to solve phylogenetic problems.