On the leaf size in Rhamnus alaternus

External aspect of Rhamnus alaternus in Les Planes, near the 'Cap of Sant Antoni', Xàbia, Alicante

One of the Filmed's species showing more morphological variability rates is Rhamnus alaternus L. In Mediterranean Spain, most populations use to be shrubs (up to 2-2,5 m tall) small-leaved, showing rigid, spiny, little leaves (2-3 cm long). However, the populations of the Thyrrenic and Central Mediterranean area often are big-leaved trees, using to overpass 4 cm in length. Some relictic populations found in the Valencian Community (Eastern Spain) are big-leaved (up to 6-7 cm in length) trees (up to 5-6 m tall), bearing brilliant, lauroid leaves, entire or slighty denticulated. The most important population have been found in the Nature Park 'El Montgó' (Dénia and Xàbia, NE of Alicante), in the so-called 'dianic' area, the Easternmost continental outcroop of the Betic mountains, sharing most of its plant checklist with the island of Eivissa/Ibiza -nowadays forming part of the Balearic archipelago, but belonging the Betic cordillera by the end of the Miocene-. These stunning plants only live in karstic soils of the 'Cap de Sant Antoni' and its surrounding plateau ('Les Planes de Xàbia'), and their external aspect is like the trees of the same species found in the calcareous grounds of Minorca (Balearic Islands). The molecular analyses developed by the project FILMED will clarify the relationships between the Montgo and the Balearic Islands for this species. Where was really born this species?.

Leaf of Rhamnus alaternus from 'Les Planes de Xàbia' (comparison scale in cm)