Genista anglica (Fabaceae): One very diverse species or one species complex?

Genista anglica represents a widely distributed group of shrubs in the Iberian Peninsula, as well as in the North of the Moroccan Mountains, the South of Italy and in most oceanic territories of Western Europe, with its northern limit in Sweden. Up to five different species within the group have been described in these territories: Genista ancistrocarpa, G. acutifolia, G. brutia and G. silana, as well as G. anglica sensu stricto. The diversity of Genista anglica sensu lato as well as the phylogenetic patterns that have generated this diversity have been analyzed through the use of nuclear (ITS, ETS) and chloroplastic (trnL, trnL-F, rbcL, matK) DNA sequences. Our results show that the group probably originated in the West of the Iberian Peninsula and subsequently spread to the rest of the European oceanic territories. Additionally, the results support the idea that the presence of a group of plants in the South of Italy, where G. brutia and G. silana were previously described, has been the consequence of the introduction of seeds collected in the Northwest of the Iberian Peninsula. Our results also indicate that, in contrast to some authors, the populations from the West of the Iberian Peninsula are not isolated and, consequently, they should be grouped into one species with high diversity, therefore differentiation into different taxa is no longer adequate.