The laurel forests of the Canary Islands are a unique ecological zone created by the cool and humid northeastern trade winds on the islandsí northern slopes. These evergreen forests have several monotypic endemic genera in addition to many endemic species which are restricted to this ecological zone in the Canaries. It has been suggested that most of the endemic plant species of the laurel forest represent relictual elements of the flora which existed in the Mediterranean basin during the Tertiary. These isolated taxa that have not radiated into other ecological zones of the islands are considered as typical examples of ancient Mediterranean stocks from the Tertiary. Sambucus is an example of this kind of relictual taxa. This genus has only one endemic species (S. nigra subsp. palmensis) which is restricted to the laurel forests of the islands of Tenerife, La Gomera, Gran Canaria, and La Palma. S. nigra subsp. palmensis is considered as one of the most rare of the laurel forest and special funds from the European Union (Life Program) have been allocated for its conservation. A molecular phylogeny of nucleotide sequences of the Internal Transcribed Spacers of the nuclear ribosomal DNA of all the species of Sambucus reveals: (1) S. nigra subsp. palmensis has a derived position in the phylogeny which suggest that it colonized the laurel forest recently and, (2) the ITS sequences of S. nigra, S. nigra subsp. palmensis and S. nigra subsp. maderensis are nearly identical. Our results concord with previous morphological studies which suggested that S. nigra subsp. palmensis can be considered subspecies of Sambucus nigra. These results have conservation consequences, mostly concerning priorities for conservation of the unique plant biodiversity of the laurel forest of the Canary Islands.

Key words: Canary Islands, conservation, molecular phylogenies, Sambucus