Molecular approach to the phylogeny and systematics of Cytisus (Leguminosae) and related genera based on nucleotide sequences of nrDNA (ITS region) and cpDNA (trnL-trnF intergenic spacer)

Phylogenetic relationships of Cystisus and allied genera (Argyrocytisus, Calicotome, Chamaecytisus, Cytisophyllum, and Spartocytisus) were assessed by analysis of sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-trnF intergenic spacer. Genera of the Genista-group (Chamaespartium, Echinospartum, Genista, Pterospartum)(11111111, Spartium, Teline and Ulex) were included to check the position of Cystisus species transferred to Teline. The tree obtained by combining both sets of data indicates that the Genista, and Cytisus groups form two separate clades. Cytisus heterochrous and C. tribracteolatus are more closely related to the Cystisus-group, thus their transfer to Teline is not supported by molecular data. Cytisus fontanesii (syn. Chronanthos biflorus) groups With Cytisophyllum sessilifolium and Cytisus heterochrous within the Cytisus-group. Similarly, Argyrocytisus battandieri falls within the Cytisus-group as a well differentiated taxon. All these taxa seem to have early diverged from the Cytisus-group Lip. Their taxonoinic rank should be reconsidered to better reflect their phylogenetic separation from Cytisus. On the contrary, Chamaecytisus proliferus bind Spartocytisus supranubius enter in the main core of Cytisus, and they should better be included in sections or Cytisus (sect. Tubocytisus and Oreosparton, respectively). Sect. Spartopsis is not monophyletic and the position of several species, currently included in this section, deserves reevaluation: C. arboreus aggregate is closely related to C. villosus (sect. Cytisus) mid to Calicotome; C. striatus is closely related to Cytisus sect. Alburnoides; mid the position of C. commutatus (incl. C. ingramii) remains Unclear. The relationships mid positioning of several minor taxa (C. transiens, C. megalanthus, and C. maurus) dire also discussed.