Molecular characterization of Hedera (Araliaceae) from Atlantic Iberian Peninsula

The Atlantic territories of western Europe and their surrounding areas are cohabited by two different species of ivies (Hedera), which are morphologically very similar, although they present different ploidy levels: Hedera helix (2x) and Hedera hibernica (4x). Concerning the northwest Atlantic Iberian territories and their surrounding areas, there are discrepancies regarding the identity of Hedera individuals at the specific level, since they have been identified as exclusively H. hibernica, but also as belonging to both species. In this context, we have aimed to determine whether the Hedera found in Atlantic Iberian Peninsula (Cantabrian Mountains territories and their surrounding areas) belong to H. helix, H. hibernica or to both. In order to achieve this, high-copy nuclear marker Internal Transcribed Spacer (ITS) and low-copy nuclear marker Granule-bound starch synthase I (GBSSI) were analyzed and compared to the results of Hedera samples from Central Europe and the Spanish Mediterranean Basin. Combined analyses of ITS-GBSSI datasets discriminate the species Hedera helix and Hedera hibernica, and our data suggest that H. hibernica is the only representative of Hedera in the Atlantic Iberian territories.