Introduction
Echinocereus is a diverse genus that includes over five dozen species that are prized by hobbyists. The species are grouped into eight sections. In previous phylogenetic analyses, useful clade information was not clearly shown, and the relationships of the groups to each other could not be determined.
The Details
Several types of evidence can clear up relationships because more data is available Thus, the authors of this paper conducted a phylogenetic study using 44 morphological (physical) characters and six DNA sequences to sort out the relationships. A second Bayesian analysis (a type of statistical analysis) along with primary data gave a phylogenetic tree (relatedness diagram) that agreed with all data.
Eight clusters of species were identified by the tree, and these analyses demonstrated that all the species are descended from a common ancestor. Clear infrageneric classification was not obtained. Overall, the authors data allowed them to propose a new sectional classification consisting of eight Echinocereus groups.
Additonal Reading: Phylogeny in Echinocereus
