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Phylogenetic relationships of Adenocarpusspecies were assessed by sequence analyses of the ITS and 3' end of ETS (nrDNA) regions and the trnL–trnFintergenic spacer (cpDNA). The nrDNA analysis recovered four main clades within Adenocarpus. Clades 1–3 comprise morphological and molecularly well–differentiated species that occur in the western Mediterranean realm. Clade 4 comprises three distinctive endemic species from the Canary Islands, an endangered Algerian endemic, and a set of species close to A. complicatuswith distinct geographical areas but with little molecular variation between taxa. The latter species are centred in the Iberian Peninsula but also distributed along the Mediterranean basin (from the Iberian Peninsula to Turkey). The phylogenetic position of A. mannii, a morphologically distinctive species with a unique afro–tropical distribution, is not unequivocally resolved, being sister to clade 3 in the ETS tree but to clade 4 in the ITS tree. Rates of evolution and ages of divergence of major groups were estimated using nonparametric rate smoothing with a fixed calibration point of 41.2 Ma and constraining the node of the separation of Anarthrophyllumand Mediterranean Genisteae at a minimum age of 13.6 and a maximum of 25.8 Ma. The estimated ages indicate that the diversification of Adenocarpusand first separation of two lineages may have occurred during the onset and the wake of the profound Middle Miocene cooling episode. One of the lineages separated rapidly into two groups (clades 1 and 2) while the second one led to clade 3, A. manniiand clade 4. Clades 1, 2 and 3 differentiated into the present species soon after these major events whereas clade 4 radiated much later, during the Pliocene.

Genetic distances among populations and phylogenetic hypothesis concerning origin and diversification of Cytisus purgans s.l. are inferred by analysis of the ITS and ETS regions (nrDNA) and the trnL-trnF intergenic spacer (cpDNA). Cytisus purgans s.l., a shrub of western Mediterranean mountains, consists of two evolutionary units: C. balansae (Boiss.) Ball (Morocco, Algeria, southern Spain) and C. oromediterraneus Rivas Mart. & al. (France, Portugal, Andorra, central and northern Spain). The two units are related to different Cytisus groups, in Bayesian and Maximum Parsimony analyses, and may be genetically unrelated, their morphological similarities being the result of convergence. However, the incongruence in the position of both species in the ITS tree and the ETS and trnL-trnF trees suggests an alternative explanation. Genetic differentiation could be due to lineage sorting of allelic polymorphism in the ITS region of the common ancestor, and the morphological similarities the result of morphological parallelism. Cytisus balansae conserves ITS sequences related to old Cytisus taxa; rapid radiation may have led to a western Mediterranean lineage in which C. oromediterraneus originated.