A first approach to the molecular phylogeny of the genus Echinops (Asteraceae): Sectional delimitation and relationships with the genus acantholepis

A first attempt to establish the phylogeny of the genera Echinops and Acantholepis has been carried out using the analysis of the internal transcribed spacers (ITS) sequences of the nuclear ribosomal DNA including 30 Echinops species and the only species of the monotypic Acantholepis. The results of this analysis are discussed in the light of morphological and cytogenetic characters, The genus Acantholepis is placed in a robust clade with Echinops nanus, and together they appear in a basal position to other members of Echinops. The ITS phylogeny and several other characters, such as chromosome number and nuclear DNA amount, do not agree with the sections currently recognized within Echinops. Some groups are defined in the present approach, but further studies are necessary to reach a complete, stable and natural infrageneric classification of this genus.