Molecular systematics of Echinops L. (Asteraceae, Cynareae): A phylogeny based on ITS and trnL-trnF sequences with emphasis on sectional delimitation

Abstract

[EN] The monogeneric subtribe Echinopsinae of Cynareae (Asteraceae) was analysed using nrDNA ITS and plastid trnLtrnF for 81 of the ca. 120 species, representing all Echinops sections except Cenchrolepis and Pterolepis. Maximum parsimony and Bayesian analyses were used for each dataset and for the combined data. The resulting molecular phylogenetic framework resolves Echinops as monophyletic and confirms the inclusion of E. acantholepis (= Acantholepis orientalis) within the genus. Echinops is divided into two lineages, one consisting of E. sect. Chamaechinops and sect. Acantholepis (almost exclusively annual or biennial), and the other the remaining sections (almost all perennial). Our results support an infrageneric classification of Echinops into nine previously recognized sections: Acantholepis (= Nanechinops), Chamaechinops, Echinops (= Terma), Hamolepis, Hololeuce, Oligolepis, Phaeochaete, Psectra and Ritropsis, all resolved as strongly monophyletic after some species relocations. The status of E. sect. Phaeochaete and the sectional assignment of E. onopordum, E. pungens and E. transcaucasicus remain to be clarified. The evolution of involucral bracts is congruent with the phylogenetic framework and supports the sectional classification. Annual pollen type does not constitute an autapomorphy of the clade grouping the annuals but may represent the ancestral character state for the entire genus.